Biodegradation of Bombyx mori silk fibroin fibers and films
Biodegradation of Bombyx mori silk fibroin fibers and films
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DOI：
10.1002/app.13393
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发表时间：
2004-02-15
影响因子：
3
通讯作者：
Tsukada, M
中科院分区：
文献类型：
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作者：
Arai, T;Freddi, G;Tsukada, M
通过将纤维和膜与蛋白水解酶（F型胶原酶、I-S型α-糜蛋白酶、XXI型蛋白酶）孵育1至17天，研究了桑蚕丝丝素蛋白的体外生物降解。暴露于蛋白水解攻击的丝纤维的样品重量和聚合度的变化可以忽略不计。然而，拉伸性能受到显着影响，如所示的下降的强度和伸长率作为降解时间的函数。孵育后，与蛋白水解酶，丝膜表现出显着减少的样品重量和聚合度，其程度取决于酶的类型，酶与底物的比例，和降解时间。蛋白酶比α-糜蛋白酶或胶原酶更具攻击性。抗酶降解的膜片段富含甘氨酸和丙氨酸。FT-IR测试表明，生物降解膜的结晶度增加。丝膜的可溶性降解产物由一系列大小差异很大的肽组成，这些肽来源于丝素蛋白链的无定形序列。生物降解纤维的表面粗糙度增加，而薄膜显示表面裂纹和空腔与内部空隙分离的纤维样元素。(C)2003 Wiley Periodicals，Inc.
The bi vitro biodegradation of Bombyx mori silk fibroin was studied by incubating fibers and films with proteolytic enzymes (collagenase type F, a-chymotrypsin type I-S, protease type XXI), for times ranging from 1 to 17 days. The changes in sample weight and degree of polymerization of silk fibers exposed to proteolytic attack were negligible. However, tensile properties were significantly affected, as shown by the drop of strength and elongation as a function of the degradation time. Upon incubation with proteolytic enzymes, silk films exhibited a noticeable decrease of sample weight and degree of polymerization, the extent of which depended on the type of enzyme, on the enzyme-to-substrate ratio, and on the degradation time. Protease was more aggressive than a-chymotrypsin or collagenase. Film fragments resistant to enzymatic degradation were enriched in glycine and alanine. FT-IR measurements showed that the degree of crystallinity of biodegraded films increased. Soluble degradation products of silk films consisted of a range of peptides widely differing in size, deriving from the amorphous sequences of the silk fibroin chains. Biodegraded fibers showed an increase of surface roughness, while films displayed surface cracks and cavities with internal voids separated by fiber-like elements. (C) 2003 Wiley Periodicals, Inc.