Faculty of Fiber Science and Engineering, Kyoto Institute of Technology, Matsugasaki, Sakyo, Kyoto 606-8585, Japan.
Faculty of Fiber Science and Engineering, Kyoto Institute of Technology, Matsugasaki, Sakyo, Kyoto 606-8585, Japan.
Int J Biol Macromol. 2021 Nov 30;191:1017-1025. doi: 10.1016/j.ijbiomac.2021.09.125. Epub 2021 Oct 1.
We recently reported that a highly homogeneous aqueous suspension of fibroin nanofiber (FNF) can be simply obtained by mechanical water-grinding a heterogeneous aqueous fibroin slurry and that the FNF in the suspension preserves the native β-sheet secondary structure during this mechanical treatment. The current study reports the surface properties of well-preserved crystalline structure novel FNF film from water-grinding preparation as compared with those of typical, conventionally prepared regenerated fibroin (RF) film. RF film was not treated with alcoholic solutions and was verified to be amorphous from a WAXD diffraction diagram. The air-side surfaces of the FNF semi-crystalline and RF amorphous films were studied to clarify differences using scanning electron microscopy (SEM), atomic force microscopy (AFM), attenuated total reflection Fourier transform infrared spectroscopy (ATR-FTIR), static water contact angle, and X-ray photoelectron spectroscopy (XPS). The well-preserved crystalline in the FNF film was found to exist near a slightly deep surface region and to act as a physically cross-linking domain, governing the molecular motions of the amorphous polypeptide chains at the very shallow surface region.
我们最近报道称，通过机械水研磨异质丝素水浆，可以简单地获得高度均匀的丝素纳米纤维（FNF）水悬浮液，并且在该机械处理过程中，悬浮液中的 FNF 保留了天然的β-折叠二级结构。与典型的常规制备的再生丝素（RF）膜相比，本研究报告了水研磨制备的保存完好的结晶结构新型 FNF 膜的表面性能。RF 膜未经醇溶液处理，从 WAXD 衍射图中证实为非晶态。使用扫描电子显微镜（SEM）、原子力显微镜（AFM）、衰减全反射傅里叶变换红外光谱（ATR-FTIR）、静态水接触角和 X 射线光电子能谱（XPS）研究了 FNF 半结晶和 RF 非晶膜的空气侧表面，以阐明差异。在 FNF 膜中发现保存完好的结晶存在于稍深的表面区域附近，并作为物理交联域，控制非常浅的表面区域中无定形多肽链的分子运动。
