Department of Chemical Engineering, Aragon Institute of Nanoscience (INA), University of Zaragoza, Campus Río Ebro-Edificio I+D, C/Poeta Mariano Esquillor S/N, 50018-Zaragoza, Spain.
Nanoscale. 2014 Aug 7;6(15):9230-40. doi: 10.1039/c4nr01588f.
PEGylated magneto-plasmonic nanoparticles with a hollow or semi-hollow interior have been successfully synthesized and their physico-chemical characteristics have been investigated. The hollow interior space can be used to store drugs or other molecules of interest whereas magnetic characterization shows their potential as contrast agents in magnetic resonance imaging (MRI) applications. In addition, their plasmonic characteristics in the near infrared (NIR) region make them efficient in photothermal applications producing high temperature gradients after short irradiation times. We show that by controlling the etching conditions the inner silica shell can be selectively dissolved to achieve a hollow or semi-hollow interior without compromising the magnetic or plasmonic characteristics of the resulting nanoparticles. Magnetic measurements and transmission electron microscopy observations have been used to demonstrate the precise control during the etching process and to select an optimal concentration of the etching reagent and contact time to preserve the inner superparamagnetic iron oxide-based nanoparticles and the plasmonic properties of the constructs. Drug loading capabilities were also evaluated for both semi-hollow and as-synthesized nanoparticles using Rhodamine B isothiocyanate as a model compound. The nanoparticles produced could be potentially used as "theranostic" nanoparticles with both imaging capabilities and a dual therapeutic function (drug delivery and hyperthermia).
具有中空或半中空内部的聚乙二醇化磁等离子体纳米粒子已被成功合成，并对其物理化学特性进行了研究。中空内部空间可用于储存药物或其他感兴趣的分子，而磁性特性表明它们在磁共振成像（MRI）应用中具有作为造影剂的潜力。此外，它们在近红外（NIR）区域的等离子体特性使它们在光热应用中非常有效，在短时间的照射后产生高的温度梯度。我们表明，通过控制蚀刻条件，可以选择性地溶解内部的硅壳，以实现中空或半中空的内部结构，而不会损害所得纳米粒子的磁性或等离子体特性。磁测量和透射电子显微镜观察已被用于证明在蚀刻过程中的精确控制，并选择最佳的蚀刻试剂浓度和接触时间，以保留内部的超顺磁性氧化铁基纳米粒子和结构的等离子体特性。还使用罗丹明 B 异硫氰酸酯作为模型化合物评估了半空心和合成纳米粒子的药物负载能力。所制备的纳米粒子可潜在用作具有成像功能和双重治疗功能（药物输送和热疗）的“治疗诊断”纳米粒子。
