Tussah Silk Fibroin Porous Scaffolds Prepared with a Mild Self-assembly Process for Controlled Drug Release

Besides excellent biodegradability and biocompatibility,a useful tissue engineering scaffold should provide favorable surface properties,outstanding mechanical strength and controlled drug release property. In this paper,a mild process to prepare porous tussah silk fibroin（ TSF） scaffolds from aqueous solution was described. The n-butanol was used to control the self-assembly of tussah silk. The scaffolds with different TSF concentrations and the same volume showed differences in pore size and distribution. The maximum porosity of the poprepared porous scaffolds was 80% in this paper. And the pore size of the prepared porous scaffolds with different concentrations was between 10μm and 230 μm. X-ray diffraction（ XRD） analysis revealed that amorphous TSF was crystallized to β-sheet secondary structure upon gelatin. The TSF scaffolds for controlled drug release was studied and the result showed that the time of drug release was significantly longer. The produced TSF scaffolds with sustained drug release have potential application in tissue engineering.     

正压式狭缝牵伸器内部结构参数的优化

依据气体动力学不等熵流动理论,采用带旋流修正的κ-ε湍流模型对正压式狭缝牵伸器内部流场进行数值计算,得出正压式狭缝牵伸器参数引射段长度、狭缝宽度、牵伸段长度、空气刀口距离及喷射角对流场内压力和速度的影响,并提出了各参数的最优化数值.计算结果可为牵伸器内部结构的最优化设计提供理论依据,为提高长丝拉伸效率和拉伸速度给出了研究方向.