Preperation of heparin-immobilized liquid crystalline hydroxypropyl cellulose ester and their blood compatibility

Event Abstract Back to Event Preperation of heparin-immobilized liquid crystalline hydroxypropyl cellulose ester and their blood compatibility Mei Tu1, Jupeng Zhao1, Yang Chen1 and Rong Zeng1 1 Jinan University, Department of Materials Science and Engineering, China Introduction: Hemocompatibility is very essential for the blood-contacting medical devices[1] because of coagulation and thrombosis still remaining a major problem for them. To Address these problems, a number of modification technologies, in which, surface heparinization is regarded as an effective way to improve the blood compatibility of materials[2, 3]. Liquid crystal molecules have been verified behaving like mobile plasma membranes due to their phase transition property that make them biocompatible and useful as anticoagulant components. In this study, heparin-grafted liquid crystalline hydroxypropyl cellulose ester was prepared via chloroformylation reaction and then Micheal addition of hydroxypropyl cellulose, and the surface morphology, crystalline behaviour, and blood compatibility for the heparinized materials were investigated. Materials and Methods: Hydroxypropyl cellulose ester with low degree of substitution(OPCL, D.S=0.8) was prepared via esterification of HPC (100,000 Da) [4], and then esterification again with acryloyl chloride to obtain octanoyl-,acryloyl-hydroxypropyl cellulose ester (OPPC), finally heparin (Hep, >150 IU/mg)-immobilization with concentration of 5mg/mL, 10mg/mL, 30mg/mL and 50mg/mL respectively, labeled as 5Hep-OPPC, 10Hep-OPPC, 30Hep-OPPC and 50Hep-OPPC respectively, to obtain Hep-OPPCs. All Hep-OPPCs were firstly performed characterization by ATR-FTIR, XPS, XRD, POM and SEM, and then blood compatibility evaluation including haemolysis, PRT, APTT, PT, complement activation and platelet attachment. Results and Discussion: ATR-FTIR and XPS analysis indicated the heparin had been immobilized on the OPPC surface. XRD patterns showed that Hep-OPPCs had lower crystallinity and an almost amorphous structure, and surface morphology observations presented the liquid crystalline color texture(Fig.1), indicating Hep-OPPCs still presented liquid crystalline feature. The blood compatibility evaluations demonstrated that HR values of Hep-OPPCs were much lower than the recommended value of 5%[5], and SEM images of platelet morphology showed that almost no substantial platelet attachment was found on the Hep-OPPC surfaces (Fig.2), suggesting minor activation and excellent anticoagulant property after heparinization. PRT, APTT and PT assays were measured here to further evaluate the anticoagulant properties of Hep-modified materials. Hep-OPPCs showed significant prolongation of PRT (354-412s) compared to the OPCL (207s), and the APTT and PT values appeared prolonged in comparison with the OPCL (Fig.3a), indicating less activation to the intrinsic coagulation system and effective hemocompatibility. The morphologic observation of erythrocytes on the material surface showed that erythrocytes exhibited the normal biconcave profile and no apparent deformations, demonstrating the Hep-OPPCs had no deleterious effects on erythrocytes morphology[11] and showed good hemocompatibility. ELISA assay showed all Hep-OPPCs had effectively lower concentrations of C3a than the refenence sample (Fig.3b) and the OPCL, indicating that the Hep-modification on the OPCL membrane could successfully inhibit the formation of soluble C3a in blood plasma[6]. Conclusions: The heparin was successfully immobilized on the liquid crystalline substrate OPCL and the Hep-OPPCs still presented liquid crystalline feature. The modified membranes showed much better blood compatibility than the OPCL, including longer plasma recalcification time, low activation of platelets, suppressed platelet adhesion and activation of C3a, and prolonged APTT and PT resulting from the synergy between anticoagulant function of heparin and liquid crystalline feature. This work was supported by National Nature Science Foundation of China (31170911,81272052, 31440043), the Fundamental Research Funds for the Central Universities (21615436), Science and Technology Program of Guangzhou, China (201508020035) and Macao science and Technology Development Fund (064/2013/A2).References:[1] G.C. Li, FMg Zhang, Y.Z. Liao, P. Yang, N. Huang. Colloids Surf. B: Biointerfaces. 2010,81, 255.[2] A.L. Gao, F. Liu, L.X. Xue. J. Membrane Sci. 2014, 452, 390.[3] Q. Gao, Y.H. Chen, Y.L. Wei, X.D. Wang, Y.L. Luo. Surf. Coat. Tech. 2013, 228, S126.[4] W.Q. Han, Master's Thesis, Jinan University, 2010.[5] F. Shen, E.L. Zhang, Z.J. Wei. Mater. Sci. Eng. C. 2010, 30,369.[6] M.Tang, J.M. Xue, K.L. Yan, T. Xiang, S.D. Sun, C.S. Zhao. J. Colloid Interface Sci. 2012, 386, 428. Keywords: Biomimetic, Biocompatibility, bioactive interface, hemocompatiblility Conference: 10th World Biomaterials Congress, Montréal, Canada, 17 May - 22 May, 2016. Presentation Type: Poster Topic: Biomaterials in thrombosis and hemostasis Citation: Tu M, Zhao J, Chen Y and Zeng R (2016). Preperation of heparin-immobilized liquid crystalline hydroxypropyl cellulose ester and their blood compatibility. Front. Bioeng. Biotechnol. Conference Abstract: 10th World Biomaterials Congress. doi: 10.3389/conf.FBIOE.2016.01.02541 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. 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