Oxidative biodegradation mechanisms of biaxially strained poly(etherurethane urea) elastomers.
Oxidative biodegradation mechanisms of biaxially strained poly(etherurethane urea) elastomers.
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双轴应变聚（醚型聚氨酯脲）弹性体的氧化生物降解机制。
DOI：
10.1002/jbm.820290309
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发表时间：
1995
期刊：
影响因子：
--
通讯作者：
Anderson,JM
中科院分区：
文献类型：
--
作者：
Schubert,MA;Wiggins,MJ;Schaefer,MP;Hiltner,A;Anderson,JM
作为正在进行的聚氨酯生物稳定性和生物降解研究的一部分，我们研究了一个体外系统来测试应变聚醚脲（PEUU）。最近，我们利用该系统在应变Pellethane®中再现了活体应力开裂。在本研究中，测试了受压的PEUU，以确定它是否通过与Pellethane®的共同机制降解，并进一步研究了这种降解所涉及的步骤。用α2‐巨球蛋白（α2‐Mac）蛋白溶液处理双轴应变的PEUU弹性体，然后进行H2O2/ cocl2氧化处理。通过衰减全反射傅里叶变换红外光谱、扫描电子显微镜（SEM）、化学分析电子能谱和接触角分析对应变后的PEUU样品进行了表征。这些表征技术的结果提供了确凿的证据，证明PEUU和Pellethane®的生物降解是通过共同的机制发生的。PEUU的化学变化包括聚醚软段和聚氨酯键的断裂，而硬段结构域不受影响。SEM分析表明，这种链解理导致PEUU表面出现严重的点蚀和裂纹。此外，它们的体外降解在化学和物理上准确地再现了它们的体内降解。这一结果证实，在体内，负责PEUUs生物降解的主要物种是羟基和/或氢过氧化物自由基。与直接在H2O2/CoCl2中处理相比，α2‐Mac预处理提高了降解率。随着PEUU软段链的断裂，降解产物被提取到处理溶液或环境中。最后，提出了一种新的聚醚软段交联降解PEUUs的机理。©1995 John Wiley & Sons, Inc
As part of ongoing studies in polyurethane biostability and biodegradation, we have investigated anin vitrosystem to test strained poly(etherurethane urea) (PEUU). Recently, we utilized this system to reproducein vivostress cracking in strained Pellethane®. In this study, strained PEUU was tested to determine whether it degrades through a common mechanism with Pellethane® and to further examine the steps involved in this degradation.Biaxially strained PEUU elastomers were treated with an α2‐macroglobulin (α2‐Mac) protein solution followed by an oxidative H2O2/CoCl2treatment. Characterization of the strained PEUU specimens was performed with attenuated total reflectance‐Fourier transform infrared spectroscopy, scanning electron microscopy (SEM), electron spectroscopy for chemical analysis, and contact angle analysis. The results from these characterization techniques provide conclusive evidence that biodegradation of PEUU and Pellethane® occurs through a common mechanism. Chemical changes to the PEUU include cleavage of the polyether soft segments and urethane linkages, leaving the hard segment domains unaffected. SEM analysis shows that this chain cleavage leads to the development of severe pitting and cracking of the PEUU surface. In addition, thein vitrodegradation accurately reproduces thein vivodegradation chemically and physically. This result verifies that the primary species responsible for biodegradation of PEUUs,in vivo, are hydroxyl and/or hydroperoxide radicals. α2‐Mac pretreatment increases the rate of degradation compared to direct treatment in H2O2/CoCl2. As the PEUU soft segment chains are cleaved, the degradation products are extracted into the treatment solution or environment. Finally, a new biodegradation mechanism of PEUUs is presented that involves crosslinking of the polyether soft segments. © 1995 John Wiley & Sons, Inc.