Department of Chemical & Biomolecular Engineering, College of Engineering , Yonsei University , 50 Yonsei-ro, Seodaemun-gu , Seoul 03722 , Republic of Korea.
Biomacromolecules. 2018 Jul 9;19(7):3096-3103. doi: 10.1021/acs.biomac.8b00687. Epub 2018 Jun 22.
Many studies of drug delivery nanoplatforms have explored drug loading affinity and controlled release. The nanoplatforms can be influenced by their inherent building blocks. Natural polypeptide silk fibroin (SF) is an excellent nanoplatform material because of its high biocompatibility and unique structural properties. SF secondary structures have different properties that can be changed by external stimuli. Thus, the characterization of SF-containing platforms is strongly affected by secondary structure transformations. Structural changes can occur spontaneously, which hinders the control of structural variation in aqueous conditions. Herein, we successfully prepared a controllable secondary structure composed of SF/heparin (HEP) layer-by-layer assembled nanofilms using simple solvents (glycerol and methanol). SF in the SF/HEP nanofilms takes up than 90%, which means configurations of SF have a strong effect on the character of the nanofilms. We investigated the degradation profiles of SF/HEP nanofilms depending on their β-sheet contents and demonstrated an immediate correlation between the transformation of secondary structures inside the nanofilms and the degree of degradation of nanofilms. Finally, SF/HEP nanofilms were used as a delivery platform for incorporating the anticancer drug epirubicin (EPI). We could control the loading efficiency and release profile of EPI with various β-sheet contents of the nanofilms.
许多药物输送纳米平台的研究都探讨了药物负载亲和力和控制释放。纳米平台会受到其固有构建块的影响。天然多肽丝素（SF）是一种出色的纳米平台材料，因为它具有很高的生物相容性和独特的结构特性。SF 的二级结构具有不同的性质，可以通过外部刺激进行改变。因此，含有 SF 的平台的特性强烈受到二级结构转变的影响。结构变化可能会自发发生，从而阻碍在水相条件下控制结构变化。在此，我们成功地使用简单溶剂（甘油和甲醇）制备了由 SF/肝素（HEP）层层组装而成的可控二级结构纳米薄膜。SF/HEP 纳米薄膜中 SF 的含量超过 90%，这意味着 SF 的构型对纳米薄膜的特性有很强的影响。我们研究了 SF/HEP 纳米薄膜的降解曲线，取决于它们的β-折叠含量，并证明了纳米薄膜内部二级结构的转变与纳米薄膜降解程度之间存在直接的相关性。最后，SF/HEP 纳米薄膜被用作包载抗癌药物表阿霉素（EPI）的输送平台。我们可以通过纳米薄膜的不同β-折叠含量来控制 EPI 的载药效率和释放曲线。
