School of Materials Science and Engineering, Tianjin Key Laboratory of Composite and Functional Materials, Tianjin University, Tianjin, 300354, China.
Tianjin First Center Hospital, Tianjin, 300192, China.
Biomater Sci. 2016 Oct 18;4(11):1673-1681. doi: 10.1039/c6bm00597g.
Our team has previously reported a high strength thermoplastic supramolecular polymer hydrogel. However, the hydrogel required injection temperatures outside the physiological range therefore preventing its use in a living environment. In this article, we reported a thermoresponsive supramolecular copolymer hydrogel p(N-acryloyl glycinamide-co-acrylamide) (PNAGA-PAAm), which can be injected at temperatures within the physiological range. We used rheological measurements to demonstrate that the transition temperature (upper critical solution temperature) of both the moduli and gel-sol could be finely adjusted by controlling both the ratio and concentration of the monomer. Adding iohexol (contrast agent) in PNAGA-PAAm hydrogels contributed to the decreased moduli and gel-sol transition temperature due to weakening of the hydrogen bonding interactions. The cytocompatible and hemocompatible PNAGA-PAAm sol mixed with iohexol was injected into the renal arteries of rabbits through a microcatheter at a temperature within the high biological range. The transition from the injection temperature (high biological range) to body temperature (basal for the animals) quickly solidified the embolic agent without the occurrence of dehydration, therefore overcoming the main limitation of LCST-typed poly(N-isopropylacrylamide) previously reported. Angiography and histological examination demonstrated the successful embolization of both renal arteries and no recanalization was observed after 8 weeks. The PNAGA-based supramolecular copolymer hydrogel is a novel embolic agent that allows for the occlusion of larger sized arteries in a biocompatible environment.
我们的团队之前报道了一种高强度的热塑性超分子聚合物水凝胶。然而，该水凝胶需要在生理范围之外的注射温度下使用，因此无法在活体环境中使用。在本文中，我们报道了一种热响应性的超分子共聚物水凝胶 p（N-丙烯酰基甘氨酸酰胺-co-丙烯酰胺）（PNAGA-PAAm），它可以在生理范围内的温度下进行注射。我们使用流变学测量来证明，通过控制单体的比例和浓度，可以精细地调整模量和凝胶-溶胶的转变温度（上临界溶液温度）。在 PNAGA-PAAm 水凝胶中添加碘海醇（造影剂）会由于氢键相互作用的减弱而导致模量降低和凝胶-溶胶转变温度降低。可注射的、细胞相容性和血液相容性的混合了碘海醇的 PNAGA-PAAm 溶液通过微导管在生理范围内的温度下注入到兔子的肾动脉中。从注射温度（高生理范围）到体温（动物的基础体温）的转变迅速使栓塞剂凝固，而不会发生脱水，从而克服了之前报道的 LCST 型聚（N-异丙基丙烯酰胺）的主要限制。血管造影和组织学检查显示，双侧肾动脉均成功栓塞，8 周后未见再通。基于 PNAGA 的超分子共聚物水凝胶是一种新型的栓塞剂，可在生物相容的环境中闭塞较大尺寸的动脉。
