State Key Laboratory for Modification of Chemical Fibers and Polymer Materials, College of Material Science and Engineering, Donghua University , 201620 Shanghai, P. R. China.
Materials Science and Technology of Polymers, MESA+ Institute of Nanotechnology, University of Twente , P.O. Box 217, 7500 AE Enschede, The Netherlands.
ACS Appl Mater Interfaces. 2017 Jan 11;9(1):901-908. doi: 10.1021/acsami.6b13097. Epub 2016 Dec 27.
Hydrogels with rapid and strong response to external stimuli and possessing high elasticity and strength have been considered as platform materials for numerous applications, e.g., in biomaterials engineering. Thermoresponsive hydrogels based on semi-interpenetrating polymer networks (semi-IPN) featuring N-isopropylacrylamide with copolymers of poly(N-isopropylacrylamide-co-hydroxyethyl methacrylate) p(NIPAM-HEMA) chains are prepared and described. The copolymer was characterized by FTIR, NMR, and GPC. The semi-IPN structured hydrogel and its responsive properties were evaluated by dynamic mechanical measurements, SEM, DSC, equilibrium swelling ratio, and dynamic deswelling tests. The results illustrate that the semi-IPN structured hydrogels possess rapid response and high elasticity compared to conventional pNIPAM hydrogels. By using a microfluidic device with double coaxial laminar flow, we succeeded in fabricating temperature responsive ("smart") hydrogel microfibers with core-shell structures that exhibit typical diameters on the order of 100 μm. The diameter of the fibers can be tuned by changing the flow conditions. Such hydrogel fibers can be used to fabricate "smart" devices, and the core layer can be potentially loaded with cargos to incorporate biological function in the constructs. The platforms obtained by this approach hold promise as artificial "muscles", and also "smart" hydrogel carriers providing a unique biophysical and bioactive environment for regenerative medicine and tissue engineering.
具有对外界刺激快速、强烈响应的高弹性和高强度的水凝胶被认为是许多应用的平台材料，例如在生物材料工程中。本文制备并描述了基于半互穿聚合物网络（semi-IPN）的温敏水凝胶，该网络以 N-异丙基丙烯酰胺为基础，与聚（N-异丙基丙烯酰胺-co-羟乙基甲基丙烯酸酯） p（NIPAM-HEMA）链共聚。通过傅里叶变换红外光谱（FTIR）、核磁共振（NMR）和凝胶渗透色谱（GPC）对共聚物进行了表征。通过动态力学测量、SEM、DSC、平衡溶胀比和动态溶胀试验评估了半 IPN 结构水凝胶及其响应性能。结果表明，与传统的 pNIPAM 水凝胶相比，半 IPN 结构水凝胶具有快速响应和高弹性。通过使用具有双同轴层流的微流控装置，我们成功地制造了具有核壳结构的温敏（“智能”）水凝胶微纤维，其典型直径约为 100μm。通过改变流动条件可以调节纤维的直径。这种水凝胶纤维可用于制造“智能”器件，并且芯层可以潜在地装载货物，以在构建体中纳入生物功能。通过这种方法获得的平台有望成为人工“肌肉”，也是提供独特的生物物理和生物活性环境的“智能”水凝胶载体，用于再生医学和组织工程。
