Water-insoluble silk films with silk I structure.
Water-insoluble silk films with silk I structure.
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DOI：
10.1016/j.actbio.2009.10.041
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发表时间：
2010-04
影响因子：
9.7
通讯作者：
Kaplan, David L.
中科院分区：
文献类型：
--
作者：
Lu, Qiang;Hu, Xiao;Wang, Xiaoqin;Kluge, Jonathan A.;Lu, Shenzhou;Cebe, Peggy;Kaplan, David L.
水不溶性再生丝材料通常通过增加β-折叠含量（丝II）来获得。在本研究中，通过控制桑蚕丝溶液的非常缓慢的干燥来制备水不溶性丝膜，从而形成以丝I而不是丝II结构为主的稳定膜。广角X射线散射(WAXS)表明，缓慢干燥稳定的丝膜主要由丝I而不是丝II组成，而水退火和甲醇退火的丝膜具有较高的丝II含量。通过缓慢干燥制备的丝膜在核心具有纳米丝的球状结构。核心区域由丝I和丝II组成，这些区域被包含无规、转角和α螺旋二级结构的亲水性纳米丝包围。缓慢干燥制备的不溶性丝膜具有独特的热性能、机械性能和降解性能。 DSC结果表明，丝I晶体在高达250°C的温度下具有稳定的热性能，在Tg以上不会结晶，但在比丝II结构更低的温度下会降解。与水退火和甲醇退火薄膜相比，通过缓慢干燥制备的薄膜具有更好的机械延展性和更快的酶降解速度，这反映了通过流延丝薄膜后处理的差异而实现的二级结构的差异。重要的是，丝绸 I 结构是形成机械坚固的天然丝纤维的关键中间二级结构，是通过模仿自然过程的非常缓慢的干燥方法成功生成的。研究结果还指出了一种生成新型丝生物材料的新模式，可以增强机械性能，提高降解率，同时保持水不溶性和低β折叠含量。
Water-insoluble regenerated silk materials are normally achieved by increasing β-sheet content (silk II). In the present study, water-insoluble silk films were prepared by controlling very slow drying of B. mori silk solutions, resulting in the formation of stable films with dominating silk I instead of silk II structure. Wide angle x-ray scattering (WAXS) indicated that the silk films stabilized by slow drying were mainly composed of silk I rather than silk II, while water- and methanol-annealed silk films had a higher silk II content. The silk films prepared through slow drying had a globule-like structure in the core with nano-filaments. The core region was composed of silk I and silk II, and these regions are surrounded by hydrophilic nano-filaments containing random, turns, and α-helix secondary structures. The insoluble silk films prepared by slow drying had unique thermal, mechanical and degradative properties. DSC results revealed that silk I crystals had stable thermal properties up to 250°C, without crystallization above the Tg, but degraded in lower temperature than silk II structure. Compared with water- and methanol-annealed films, the films prepared through slow drying achieved better mechanical ductility and more rapid enzymatic degradation, reflective of the differences in secondary structure achieved via differences in post processing of the cast silk films. Importantly, the silk I structure, a key intermediate secondary structure for the formation of mechanically robust natural silk fibers, was successfully generated in the present approach of very slow drying, mimicking the natural process. The results also point to a new mode to generate new types of silk biomaterials, where mechanical properties can be enhanced, and degradation rates increased, yet water insolubility is maintained along with low beta sheet content.
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影响因子：
6.2
作者：
Jin, HJ;Fridrikh, SV;Kaplan, DL
通讯作者：
Kaplan, DL
影响因子：
19
作者：
Jiang, Chaoyang;Wang, Xianyan;Tsukruk, Vladimir V.
通讯作者：
Tsukruk, Vladimir V.
影响因子：
64.8
作者：
Jin, HJ;Kaplan, DL
通讯作者：
Kaplan, DL
影响因子：
4.6
作者：
Chen Chen;Cao Chuanbao;Zhu Hesun
通讯作者：
Zhu Hesun
DOI：
10.1016/0265-928x(89)80002-1
发表时间：
1989-01-01
期刊：
BIOSENSORS
影响因子：
--
作者：
DEMURA, M;ASAKURA, T;KUROO, T
通讯作者：
KUROO, T