In-line blending of electrospun fibers to generate aligned grafts with gradient properties

Abstract

Event Abstract Back to Event In-line blending of electrospun fibers to generate aligned grafts with gradient properties Alysha Kishan1, Renee Calderon2, Tyler Touchet1 and Elizabeth Cosgriff-Hernandez1 1 Texas A&M University, Biomedical Engineering, United States 2 Rice University, Bioengineering, United States Introduction: Electrospinning has gained popularity in recent years as a technique to generate fibrous scaffolds for various applications. Several researchers have utilized gradient electrospinning setups to produce scaffolds that mimic the mechanical and biochemical transitions of native tissue interfaces. However, current techniques do not allow for these gradients to be in the direction of fiber alignment, as displayed when native tendon transitions to bone. To address this limitation, we have developed an electrospinning method with fine control over gradient dimensions that also allows for gradients in the direction of fiber alignment. This technique provides a novel method to produce highly aligned scaffolds with linear gradient properties that better mimic the structure of the tendon to bone interface, as well as other transitions. Materials and Methods: Biodegradable poly(ether ester urethane)ureas (B-PURs) were synthesized with varying hard segment (HS) content using a protocol previously established by our group. 10 wt% solutions of B-PUR 30%HS and 50%HS in 1,1,1,3,3,3-hexafluoro-2-propanol were utilized for electrospinning. The solutions were loaded into syringes and connected through a y-junction to a single mixing head and needle. The flow rate of solution 1 ranged from 0.3 mL/h to 0 mL/h (decreasing 0.6mL/h each hour), while solution 2 ranged from 0 mL/h to 0.3 mL/h (increasing 0.6mL/h each hour). A voltage of 9 kV was applied to the needle tip and -8 kV was applied to the collector. The collector consisted of a wheel of parallel copper wires that rotated 180° in 6 hours (Figure 1). Gradient formation was verified by adding Rhodamine-B to solution 2. The electrospinning solution was collected hourly and the fluorescence was quantified with a plate reader. Fiber morphology was characterized with scanning electron microscopy (SEM). Results and Discussion: In contrast to most gradient setups that are based on offset spinnerets, this setup permitted gradient formation along the mesh length as a function of time and polymer feed ratio. An increase in fluorescence confirmed a continuous transition from solution 1 to solution 2 (Figure 2a). Parallel copper wires on the collector were designed to promote alignment in the direction of the gradient formation. The SEM micrographs displayed highly aligned fibers in the same direction as the gradient with uniform thickness over the course of electrospinning (Figure 2b). Current work involves in-depth characterization of these mechanical and biochemical gradients, as well as investigating the corollary impact on cellular behavior. Conclusion: This study demonstrates a novel method to produce highly aligned, gradient scaffolds that can be utilized to direct cellular behavior through a combination of topographical, biomechanical, and biochemical cues. Overall, this unique method provides additional capabilities to the researcher in mimicking the complexity of native tissue transitions. Keywords: Tissue Engineering, nanofiber, Scaffold Conference: 10th World Biomaterials Congress, Montréal, Canada, 17 May - 22 May, 2016. Presentation Type: General Session Oral Topic: Electrospinning and related technologies Citation: Kishan A, Calderon R, Touchet T and Cosgriff-Hernandez E (2016). In-line blending of electrospun fibers to generate aligned grafts with gradient properties. Front. Bioeng. Biotechnol. Conference Abstract: 10th World Biomaterials Congress. doi: 10.3389/conf.FBIOE.2016.01.00779 Copyright: The abstracts in this collection have not been subject to any Frontiers peer review or checks, and are not endorsed by Frontiers. They are made available through the Frontiers publishing platform as a service to conference organizers and presenters. The copyright in the individual abstracts is owned by the author of each abstract or his/her employer unless otherwise stated. Each abstract, as well as the collection of abstracts, are published under a Creative Commons CC-BY 4.0 (attribution) licence (https://creativecommons.org/licenses/by/4.0/) and may thus be reproduced, translated, adapted and be the subject of derivative works provided the authors and Frontiers are attributed. For Frontiers’ terms and conditions please see https://www.frontiersin.org/legal/terms-and-conditions. Received: 27 Mar 2016; Published Online: 30 Mar 2016. Login Required This action requires you to be registered with Frontiers and logged in. To register or login click here. Abstract Info Abstract The Authors in Frontiers Alysha Kishan Renee Calderon Tyler Touchet Elizabeth Cosgriff-Hernandez Google Alysha Kishan Renee Calderon Tyler Touchet Elizabeth Cosgriff-Hernandez Google Scholar Alysha Kishan Renee Calderon Tyler Touchet Elizabeth Cosgriff-Hernandez PubMed Alysha Kishan Renee Calderon Tyler Touchet Elizabeth Cosgriff-Hernandez Related Article in Frontiers Google Scholar PubMed Abstract Close Back to top Javascript is disabled. Please enable Javascript in your browser settings in order to see all the content on this page.