SUFU 2020: Liquid Crystal Elastomers as Dynamic Material For the Treatment of Urinary Incontinence

Scottsdale, AZ (UroToday.com) Dr. Philippe Zimmern and Dr. Taylor Ware’s team from The University of Texas Southwestern Medical Center and The University of Texas at Dallas showed design and prototyping of a dynamic sling made of a new class of novel material capable of reversible shape changes around the urethra. This is a Liquid crystal elastomer (LCE), a rubbery material that can be 3D printed into any shape that can fit around the urethra, offering access to personalized care.


A unique feature of this material is the ability to undergo controlled shape change in response to local temperature changes in the range of 37 °C to 45 °C. By incorporating infrared (IR)-absorbing fillers, such as PEDOT: PSS and carbon black, shape change can be triggered with IR light, where incident light selectively heats the material. This study showed different temperature ranges and shapes with varied configuration and thickness to mimic real-life urethral wall compression.
 

LCE material actuates under a temperature range of 25 °C to 45 °C. This displays the feasibility of the LCE dynamic sling actuating under tolerable temperatures within the body, avoiding thermal damage to the surrounding tissue. Actuation, in response to IR-light, is observed in the LCE-PEDOT: PSS and LCE-carbon black 3D printed samples. Figure 1 shows actuation in response to IR light of a 3D-printed LCE-carbon black sling. Stresses and strains produced by the LCE dynamic sling under simulated physiological environments can exceed 200 kPa and 60%, respectively, both greater than the stress and strain outputs of human skeletal muscle. Using this capacity to perform mechanical work and the ability to control geometry with 3D printing, the force, and deformation applied to the urethra are controlled. Deformation speed and internal temperature changes of the LCE is varied by altering filler content from 0.5 to 5 wt%.

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In the end, they concluded that a dynamic sling can be fabricated to fit the specific anatomy of each patient. This device is powered transcutaneously using IR light, which triggers a shape change in the sling material, resulting in a decrease in pressure around the urethra to facilitate voiding. Future work will involve testing device shapes and configurations in a multiparous rabbit model of incontinence.

Presented by: Seelay Tasmim1, Cedric P. Ambulo1, Mario I. Romero-Ortega1, Philippe E. Zimmern2, Taylor H. Ware1

1. The University of Texas at Dallas, Department of Bioengineering, Richardson, Texas
2. The University of Texas Southwestern Medical Center, Department of Urology, Dallas, Texas

Written by: Gina B. Carithers, the Society of Urodynamics, Female Pelvic Medicine & Urogenital Reconstruction Winter Meeting, SUFU 2020, February 25 - 29, 2020, Scottsdale, AZ