Zhang Hu, Guo Shengwei, Fu Shangyi, Zhao Yue
Département de Chimie, Université de Sherbrooke, Sherbrooke, QC J1K 2R1, Canada.
School of Material Science & Engineering, Beifang University of Nationalities, Yinchuan 750021, China.
Polymers (Basel). 2017 Jun 20;9(6):238. doi: 10.3390/polym9060238.
We report a near-infrared (NIR) light-responsive hydrogel that is capable of undergoing the gel to sol transition upon 785 nm light exposure based on a photothermal effect. The new hydrogel design relies on loading gold nanorods (AuNRs) in an ABA-type triblock copolymer, namely P(AAm⁻⁻AN)⁻⁻PDMA⁻⁻P(AAm⁻⁻AN), where P(AAm⁻⁻AN) stands for a random copolymer of acrylamide and acrylonitrile that exhibits an upper critical solution temperature (UCST) in aqueous solution and PDMA is water-soluble polydimethylacrylamide. At solution temperature below UCST, the insoluble P(AAm⁻⁻AN) blocks lead to formation of hydrogel of flower-like micelles. When the hydrogel is exposed to 785 nm NIR light, the absorption due to the longitudinal surface plasmon resonance of loaded AuNRs generates heat that raises the hydrogel temperature above UCST and, consequently, the gel-to-sol transition. The NIR light-triggered release of a protein loaded in the hydrogel was found to display a switchable fashion.
我们报道了一种近红外（NIR）光响应水凝胶，基于光热效应，该水凝胶在785 nm光照射下能够发生凝胶-溶胶转变。这种新型水凝胶设计依赖于在ABA型三嵌段共聚物P(AAm⁻⁻AN)⁻⁻PDMA⁻⁻P(AAm⁻⁻AN)中负载金纳米棒（AuNRs），其中P(AAm⁻⁻AN)代表丙烯酰胺和丙烯腈的无规共聚物，其在水溶液中表现出上临界溶液温度（UCST），而PDMA是水溶性聚二甲基丙烯酰胺。在低于UCST的溶液温度下，不溶性的P(AAm⁻⁻AN)嵌段导致形成花状胶束水凝胶。当水凝胶暴露于785 nm近红外光时，负载的AuNRs纵向表面等离子体共振引起的吸收产生热量，使水凝胶温度升高至UCST以上，从而导致凝胶-溶胶转变。研究发现，负载在水凝胶中的蛋白质的近红外光触发释放呈现出可切换的方式。
