Department of Chemistry, The College of Staten Island, and The Graduate Center, The City University of New York, Staten Island, NY 10314, USA.
Nanoscale. 2014 Nov 7;6(21):13001-11. doi: 10.1039/c4nr03748k.
The paper demonstrates a class of multifunctional core-shell hybrid nanogels with fluorescent and magnetic properties, which have been successfully developed for simultaneous optical temperature sensing, tumor cell imaging and magnetic/NIR-thermally responsive drug carriers. The as-synthesized hybrid nanogels were designed by coating bifunctional nanoparticles (BFNPs, fluorescent carbon dots embedded in the porous carbon shell and superparamagnetic iron oxide nanocrystals clustered in the core) with a thermo-responsive poly(N-isopropylacrylamide-co-acrylamide) [poly(NIPAM-AAm)]-based hydrogel as the shell. The BFNPs in hybrid nanogels not only demonstrate excellent photoluminescence (PL) and photostability due to the fluorescent carbon dots embedded in the porous carbon shell, but also has targeted drug accumulation potential and a magnetic-thermal conversion ability due to the superparamagnetic iron oxide nanocrystals clustered in the core. The thermo-responsive poly(NIPAM-AAm)-based gel shell can not only modify the physicochemical environment of the BFNPs core to manipulate the fluorescence intensity for sensing the variation of the environmental temperature, but also regulate the release rate of the loaded anticancer drug (curcumin) by varying the local temperature of environmental media. In addition, the carbon layer of BFNPs can adsorb and convert the NIR light to heat, leading to a promoted drug release under NIR irradiation and improving the therapeutic efficacy of drug-loaded hybrid nanogels. Furthermore, the superparamagnetic iron oxide nanocrystals in the core of BFNPs can trigger localized heating using an alternating magnetic field, leading to a phase change in the polymer gel to trigger the release of loaded drugs. Finally, the multifunctional hybrid nanogels can overcome cellular barriers to enter the intracellular region and light up the mouse melanoma B16F10 cells. The demonstrated hybrid nanogels would be an ideal system for the biomedical applications due to their excellent optical properties, magnetic properties, high drug loading capacity and responsive drug release behavior.
本文展示了一类具有荧光和磁性的多功能核壳杂化纳米凝胶，它们已成功开发用于同时进行光学温度传感、肿瘤细胞成像以及磁性/NIR 热响应药物载体。所合成的杂化纳米凝胶是通过将具有荧光性质的双功能纳米粒子（BFNPs，荧光碳点嵌入多孔碳壳中，超顺磁性氧化铁纳米晶簇集在核中）包覆在温敏性聚（N-异丙基丙烯酰胺-共-丙烯酰胺）[聚（NIPAM-AAm）]基水凝胶壳中制得的。杂化纳米凝胶中的 BFNPs 不仅由于嵌入多孔碳壳中的荧光碳点而表现出优异的光致发光（PL）和光稳定性，而且由于核中聚集的超顺磁性氧化铁纳米晶而具有靶向药物积累潜力和磁热转换能力。温敏性聚（NIPAM-AAm）基凝胶壳不仅可以改变 BFNPs 核的物理化学环境来操纵荧光强度以感测环境温度的变化，还可以通过改变环境介质的局部温度来调节负载的抗癌药物（姜黄素）的释放速率。此外，BFNPs 的碳层可以吸附并将 NIR 光转化为热，从而在 NIR 照射下促进药物释放，提高载药杂化纳米凝胶的治疗效果。此外，BFNPs 核中的超顺磁性氧化铁纳米晶可以在交变磁场的作用下引发局部加热，导致聚合物凝胶发生相转变，触发负载药物的释放。最后，多功能杂化纳米凝胶可以克服细胞屏障进入细胞内区域并点亮小鼠黑色素瘤 B16F10 细胞。由于其出色的光学性能、磁性、高载药能力和响应性药物释放行为，所展示的杂化纳米凝胶将成为生物医学应用的理想系统。
