Jiangxi Key Laboratory for Mass Spectrometry and Instrumentation, East China University of Technology, Nanchang 330013, P. R. China.
Department of Chemistry and Biochemistry, University of Maryland, College Park 20742, Maryland, United States.
ACS Appl Mater Interfaces. 2020 Mar 18;12(11):13521-13528. doi: 10.1021/acsami.9b23195. Epub 2020 Mar 5.
Self-rolling of a planar hydrogel sheet represents an advanced approach for fabricating a tubular construct, which is of significant interest in biomedicine. However, the self-rolling tube is usually lacking in remote controllability and requires a relatively tedious fabrication procedure. Herein, we present an easy and controllable approach for fabricating self-rolling tubes that can respond to both magnetic field and light. With the introduction of magnetic nanorods in a hydrogel precursor, a strain gradient is created across the thickness of the formed hydrogel sheet during the photopolymerization process. After the removal of the strain constraint, the nanocomposite sheet rolls up spontaneously. The self-rolling scenario of the sheet can be tuned by varying the sheet geometry and the magnetic nanorod concentration in the hydrogel precursor. The nanocomposite hydrogel tube translates in the presence of a magnetic field and produces heat upon a near-infrared (NIR) light illumination by virtue of the magnetic and photo-thermal properties of the magnetic nanorods. The self-rolling tube either opens up or expands its diameter under NIR light irradiation depending on the number of rolls in the tube. With the use of a thermo-responsive hydrogel material, we demonstrate the magnetically guided motion of the chemical-bearing nanocomposite hydrogel tube and its controlled chemical release through its light-mediated deformation. The approach reported herein is expected to be applicable to other self-rolling polymer-based dry materials, and the nanocomposite hydrogel tube presented in this work may find potential applications in soft robot and controlled release of drug.
平面水凝胶片的自卷曲代表了一种制造管状结构的先进方法，在生物医学中具有重要意义。然而，自卷曲管通常缺乏远程可控性，并且需要相对繁琐的制造工艺。在此，我们提出了一种简单可控的方法来制造对磁场和光都有响应的自卷曲管。通过在水凝胶前体中引入磁性纳米棒，可以在光聚合过程中在形成的水凝胶片的厚度上产生应变梯度。去除应变约束后，纳米复合片会自发地卷起。通过改变片的几何形状和水凝胶前体中的磁性纳米棒浓度，可以调节片的自卷曲情况。纳米复合水凝胶管在磁场的存在下会发生平移，并由于磁性纳米棒的磁和光热特性在近红外（NIR）光照射下会产生热量。自卷曲管在 NIR 光照射下会根据管内的卷数打开或扩大其直径。通过使用热响应水凝胶材料，我们展示了载药纳米复合水凝胶管在磁场引导下的运动及其通过光介导的变形进行的受控药物释放。本文报道的方法有望适用于其他自卷曲聚合物基干材料，并且本文中提出的纳米复合水凝胶管可能在软机器人和药物控制释放方面有潜在应用。
