Chongqing Key Laboratory of Ultrasound Molecular Imaging, Institute of Ultrasound Imaging, Second Affiliated Hospital, Chongqing Medical University, Chongqing, 400010, P. R. China.
Three Gorges Natural Medicine Engineering Research Center, School of Biological & Chemical engineering, Chongqing University of Education, Chongqing, 400067, P. R. China.
Sci Rep. 2017 Sep 20;7(1):11913. doi: 10.1038/s41598-017-12351-1.
Silk fibroin (SF), a FDA-approved natural protein, is renowned for its great biocompatibility, biodegradability, and mechanical properties. SF-based nanoparticles provide new options for drug delivery with their tunable drug loading and release properties. To take advantage of the features of carrier polymers, we present a one-step electrospraying method that combines SF, polyvinyl alcohol (PVA) and therapeutic drugs without an emulsion process. A distinct core-shell structure was obtained with the PVA core and silk shell after the system was properly set up. The model drug, doxorubicin, was encapsulated in the core with a greater than 90% drug encapsulation efficiency. Controllable drug release profiles were achieved by alternating the PVA/SF ratio. Although the initial burst release of the drug was minimized by the SF coating, a large number of drug molecules remained entrapped by the carrier polymers. To promote and trigger drug release on demand, low intensity focused ultrasound (US) was applied. The US was especially advantageous for accelerating the drug diffusion and release. The apoptotic activity of MDA-MB-231 cells incubated with drug-loaded nanoparticles was found to increase with time. In addition, we also observed PVA/SF nanoparticles that could elicit a drug release in response to pH.
丝素蛋白（SF）是一种经过 FDA 批准的天然蛋白质，以其良好的生物相容性、可生物降解性和机械性能而闻名。基于 SF 的纳米粒子具有可调节的药物负载和释放特性，为药物输送提供了新的选择。为了利用载体聚合物的特性，我们提出了一种一步电喷雾方法，该方法将 SF、聚乙烯醇（PVA）和治疗药物结合在一起，而无需乳液工艺。在适当设置后，系统获得了具有 PVA 核和丝素壳的独特核壳结构。模型药物阿霉素的包封效率大于 90%。通过交替 PVA/SF 比可以实现可控的药物释放曲线。尽管 SF 涂层最小化了药物的初始突释，但大量药物分子仍被载体聚合物包封。为了按需促进和触发药物释放，应用了低强度聚焦超声（US）。US 特别有利于加速药物的扩散和释放。与载药纳米粒子孵育的 MDA-MB-231 细胞的凋亡活性随时间增加。此外，我们还观察到 PVA/SF 纳米粒子可以响应 pH 值引发药物释放。
