Structure and blood compatibility of highly oriented poly(L-lactic acid) chain extended by ethylene glycol diglycidyl ether

POLYMER

卷:56

Article

Li, Zhengqiu¹  Zhao, Xiaowen¹  Ye, Lin¹  Coates, Phil²  Caton-Rose, Fin²  Martyn, Michasel² 

[1] Sichuan Univ, Polymer Res Inst, State Key Lab Polymer Mat Engn China, Chengdu 610064, Peoples R China

[2] Univ Bradford, Sch Engn Design & Technol, Bradford BD7 1DP, W Yorkshire, England

关键词: Poly (L-lactic acid) (PLLA);    Orientation;    Blood compatibility;   

DOI  :  10.1016/j.polymer.2014.11.035

来源: Elsevier

【 摘 要 】

Highly-oriented poly(L-lactic acid) (PLLA) with fibrillar structure and micro-grooves was fabricated through solid hot drawing technology for further improving the mechanical properties and blood biocompatibility of PLLA as blood-contacting medical devices. In order to enhance the melt strength and thus obtain high orientation degree, PLLA was first chain extended with ethylene glycol diglycidyl ether (EGDE). The extending degree as high as 25.79 mol% can be obtained at 0.7 wt% EGDE content. The complex viscosity, storage and viscous modulus for chain extended PLLA were improved resulting from the enhancement of molecular entanglement, and consequently higher draw ratio can be achieved during the subsequent hot stretching. The tensile strength and modulus of PLLA were improved dramatically by stretching. The stress-induced crystallization of PLLA occurred during drawing. The interfacial tension (gamma(s.blood)) between PLLA surface and blood decreased by chain extension and molecular orientation, indicating the weakened interaction between bioactive substance in the blood and the surface of PLLA. Modification and orientation could significantly enhance the blood compatibility of PLLA by prolonging clotting time and decreasing hemolysis ratio, protein adsorption and platelet activation. The bionic character of oriented PLLA and its anti-coagulation mechanism were tried to be explored. (C) 2014 Elsevier Ltd. All rights reserved.

【 授权许可】

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