Electrospun pure chitosan nanofibrous mats with high structural stability for dura mater regeneration

Event Abstract Back to Event Electrospun pure chitosan nanofibrous mats with high structural stability for dura mater regeneration Yuandong Dou1, Xianchang Sun1, Gang Guo1*, Jiahuan Dong1*, Meijiao Lu1* and Wencai Zhang1 1 Yantai Zhenghai Bio-tech Co., Ltd., China Introduction: Dura defect is a commonly encountered problem in spine- and neurosurgery. Numerous materials have been exploited as dural substitutes including autologous tissue and xenogenic materials, yet the majority still cannot meet the whole clinical requirements in dura repair[1]. Chitosan has been intensively explored as a suitable functional material for tissue regeneration. However, the successful fabrication of pure chitosan nanofibers with good structure stability through electrospinning still remains a great challenge[2]. Here, we reported the feasible preparation of pure electrospun chitosan nanofibers and their utilization for effective reconstruction of dura defect. The structural and functional performances of the chitosan dura substitutes were systemically investigated. Materials and Methods: Chitosan powders were added into the mixed solvents of hexafluoro-2-propanol and acetic acid (2 vol.%) with a 1.25% (w/v) concentration. The electrospinning process was conducted at feeding rate of 3.0 ml/h, voltage of 12.5 Kv and tip-to-collector distance of 10 cm. Structural stability evaluation was carried out through soaking in PBS for 24 h. In vitro cytocompatibility was evaluated through human dermal fibroblasts (HDF) and human umbilical vein endothelial cells (HUVEC) culture on chitosan nanofibrous mats. The cerebrospinal fluid leakage prevention and dura regeneration study were conducted through a rabbit duraplasty model. Results and Discussion: As can be seen from Figure 1, there are no obvious differences of fibrous microstructure and dimension size (insets of Fig. 1b, d) between the as-spun and soaked samples, indicating excellent structural integrity in aqueous solutions. The electrospun pure chitosan nanofibers were usually prepared using trifluroacetic acid (TFA) as solvents[3]. However, the resultant chitosan nanofibrous mats showed poor structural stability and would completely dissolve as soon as they contact neutral aqueous solutions because of the water-soluble salts formation between chitosan molecules and TFA[4]. The combination and proportion of HFP and acetic acid used in this study avoided the drawbacks of using TFA and assured the successful fabrication of pure stable chitosan nanofibers. Figure 1. SEM morphology of the as-spun chitosan nanofibers (a, b) and after 24 h soaking in PBS (c, d). Insets of b, d are the corresponding appearance photo, scale bars represent 1cm. As the main functional cells during the wound healing process, HDF and HUVEC attachment and proliferation were well supported when cultured on pure chitosan nanofibers, suggesting excellent in vitro cytocompatibility. The CSF leakage prevention operation showed no leakage of cranial methylene blue solution from the defect area covered by the chitosan nanofibers. The reconstruction results of chitosan nanofibrous substitutes on dura defect were shown in Figure 2. A freshly generated neodura-like connective tissue was found beneath the chitosan implants at the defect area after 8 weeks implantation. The histological results of the newly formed tissue showed a dense characteristic with a thick layer. The arrangement of constructed collagen fibrils within the newly formed neodura was in a highly ordered manner, which is almost the same as those of natural dura mater (Figure 2d). Figure 2. a) Chitosan nanofibers onlaid over the right durotomy site, the left site was set as blank. b) the circle indicates a newly formed neodura beneath the implants at week 8. c) Histological image of the neodura (ND) around the implanted chitosan nanofibers (CHN). d) TEM images of newly formed neodura, inset is the incised natural rabbit dura mater. Conclusion: Pure chitosan nanofibers with excellent structural stability were successfully prepared through electrospinning process without any post-treatments. This nanofibrous dura substitutes showed excellent in vitro cytocompatibility as to HDFs and HUVEC. Moreover, chitosan nanofibers displayed overall excellent performance in CSF leakage prevention and dura reconstruction, making them ideal candidates for dura substitutes. References:[1] Khorasani L, Kapur RP, Lee C, Avellino AM. Histological analysis of DuraGen in a human subject: case report. Clin Neuropathol 2008;27(5):361-4.[2] Schiffman JD, Stulga LA, Schauer CL. Chitin and chitosan: Transformations due to the electrospinning process. Polym Eng Sci 2009;49(10):1918-1928.[3] Sangsanoh P, Supaphol P. Stability Improvement of Electrospun Chitosan Nanofibrous Membranes in Neutral or Weak Basic Aqueous Solutions. Biomacromolecules 2006;7(10):2710-2714.[4] Nirmala R, Il B, Navamathavan R, El-Newehy M, Kim H. Preparation and characterizations of anisotropic chitosan nanofibers via electrospinning. Macromol Res 2011;19(4):345-350. Keywords: nanofiber, microstructure, Tissue Regeneration, polymer Conference: 10th World Biomaterials Congress, Montréal, Canada, 17 May - 22 May, 2016. Presentation Type: New Frontier Oral Topic: Biomaterials in constructing tissue substitutes Citation: Dou Y, Sun X, Guo G, Dong J, Lu M and Zhang W (2016). Electrospun pure chitosan nanofibrous mats with high structural stability for dura mater regeneration. Front. Bioeng. Biotechnol. Conference Abstract: 10th World Biomaterials Congress. doi: 10.3389/conf.FBIOE.2016.01.01956 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. * Correspondence: Dr. Gang Guo, Yantai Zhenghai Bio-tech Co., Ltd., Yantai, China, Email1 Dr. Jiahuan Dong, Yantai Zhenghai Bio-tech Co., Ltd., Yantai, China, Email2 Dr. Meijiao Lu, Yantai Zhenghai Bio-tech Co., Ltd., Yantai, China, Email3 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 Yuandong Dou Xianchang Sun Gang Guo Jiahuan Dong Meijiao Lu Wencai Zhang Google Yuandong Dou Xianchang Sun Gang Guo Jiahuan Dong Meijiao Lu Wencai Zhang Google Scholar Yuandong Dou Xianchang Sun Gang Guo Jiahuan Dong Meijiao Lu Wencai Zhang PubMed Yuandong Dou Xianchang Sun Gang Guo Jiahuan Dong Meijiao Lu Wencai Zhang 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.