Wang Shiyi, Zhu Mingmei, Zhao Liang, Kuang Dajiang, Kundu Subhas C, Lu Shenzhou
National Engineering Laboratory for Modern Silk, College of Textile and Clothing Engineering, Soochow University, Suzhou 215123, China.
3Bs Research Group, Headquarters of the European Institute of Excellence on Tissue Engineering and Regenerative Medicine, University of Minho, AvePark Barco, Taipas, Guimaraes 4805-017, Portugal.
ACS Biomater Sci Eng. 2019 Apr 8;5(4):1887-1894. doi: 10.1021/acsbiomaterials.9b00229. Epub 2019 Mar 4.
Silk fibroin has widely been used in biomedical applications for its excellent biocompatibility, degradability, and mechanical properties. Microneedles are a suitable method for transdermal drug delivery. In this work, we have prepared microneedles using silk fibroin as the main material and have added proline to change its crystal structure. The fabricated microneedles are nontoxic and degradable and show relatively slow drug release. Our results indicate that the fibroin/proline microneedles can act as carriers of insulin. Fourier transform infrared (FTIR) observations show that the structure of proline-treated fibroin is transformed from random coils to β-sheets. A more regular arrangement is formed between the molecular segments. X-ray diffraction patterns show that proline has good compatibility with fibroin and induces the secondary conformation of the microneedles to a Silk I type structure. The needles have enough strength to pierce the stratum corneum of the skin. release experiments with insulin indicate that the release time from the microneedles is maintained up to 60 h. This system of delivery may provide a painless and effective route of insulin intake for the treatment of diabetic patients.
丝素蛋白因其优异的生物相容性、可降解性和机械性能而广泛应用于生物医学领域。微针是一种适合经皮给药的方法。在这项工作中，我们以丝素蛋白为主要材料制备了微针，并添加了脯氨酸以改变其晶体结构。所制备的微针无毒且可降解，药物释放相对缓慢。我们的结果表明，丝素蛋白/脯氨酸微针可作为胰岛素的载体。傅里叶变换红外光谱（FTIR）观察表明，经脯氨酸处理的丝素蛋白结构从无规卷曲转变为β-折叠。分子片段之间形成了更规则的排列。X射线衍射图谱表明，脯氨酸与丝素蛋白具有良好的相容性，并诱导微针的二级构象转变为丝I型结构。这些微针有足够的强度穿透皮肤角质层。胰岛素释放实验表明，微针的释放时间可维持长达60小时。这种给药系统可能为糖尿病患者提供一种无痛且有效的胰岛素摄入途径。
