National Engineering Laboratory for Modern Silk, College of Textile and Clothing Engineering, Soochow University, Suzhou 215123, China.
Zhejiang Cathaya International Co., Ltd, Hangzhou 310004, China.
Biomacromolecules. 2021 Feb 8;22(2):546-556. doi: 10.1021/acs.biomac.0c01411. Epub 2021 Jan 15.
Silk fibroin films are used in tissue engineering due to their biocompatibility, optical clarity, and slow biodegradability. However, the relatively smooth surface and low permeability of these systems may limit some applications; thus, here, a method was developed to generate nano-pores in methanol or ethanol-treated silk fibroin films. The first step was to induce the formation of nanoparticles (50-300 nm diam.) in silk fibroin solutions by autoclaving. After drying in air, the films formed were treated to induce silk β-sheet structures, which condense the bulk silk phase and nanoparticles and phase separation and enlarge the space of bulk silk phase and nanoparticles. These films were then extracted with water to allow the condensed nanoparticles to escape, leaving homogeneous nano-pores (50-300 nm) in the silk fibroin matrix. The introduction of nano-pores resulted in enhanced permeability and minimized loss of the mechanical properties of the nano-porous silk fibroin films (NSFs) when compared to the un-autoclaving-treated silk fibroin films. NSFs promoted cell (human fibroblasts) proliferation and oxygen/nutrition perfusion and significantly enhanced the complete skin-thickness wound healing in a rat model, suggesting the potential use in tissue regeneration or as wound dressing biomaterials for clinical applications.
丝素蛋白薄膜由于其生物相容性、光学透明性和缓慢的生物降解性而被用于组织工程。然而，这些系统相对光滑的表面和低渗透性可能限制了一些应用；因此，在这里，开发了一种在甲醇或乙醇处理的丝素蛋白薄膜中生成纳米孔的方法。第一步是通过高压灭菌在丝素蛋白溶液中诱导形成纳米颗粒（50-300nm 直径）。在空气中干燥后，形成的薄膜经过处理以诱导丝素β-折叠结构，该结构使大块丝素相和纳米颗粒凝聚并相分离，从而扩大大块丝素相和纳米颗粒的空间。然后用去离子水提取这些薄膜，使凝聚的纳米颗粒逸出，从而在丝素蛋白基质中留下均匀的纳米孔（50-300nm）。与未经高压灭菌处理的丝素蛋白薄膜相比，纳米孔的引入增强了纳米多孔丝素蛋白薄膜（NSFs）的渗透性，同时最小化了其力学性能的损失。NSFs 促进了细胞（人成纤维细胞）的增殖和氧气/营养物质的灌注，并显著增强了大鼠模型中全层皮肤伤口的愈合，这表明它们有可能在组织再生或作为临床应用的伤口敷料生物材料中使用。
