Institut de Physique et Chimie des Matériaux de Strasbourg (IPCMS), UMR-7504 CNRS-Université de Strasbourg, 23 rue du Lœss, BP 34 67034, Strasbourg Cedex 2, France.
Centre de Recherches en Cancérologie de Toulouse UMR1037 CNRS - Inserm/Université Paul Sabatier, 1 avenue Jean Poulhes, BP 84225, 31432 Toulouse, Cedex 4, France.
Nanoscale. 2024 Aug 22;16(33):15585-15614. doi: 10.1039/d4nr01388c.
Core-shell nanocomposites made of iron oxide core (IO NPs) coated with mesoporous silica (MS) shells are promising theranostic agents. While the core is being used as an efficient heating nanoagent under alternating magnetic field (AMF) and near infra-red (NIR) light and as a suitable contrast agent for magnetic resonance imaging (MRI), the MS shell is particularly relevant to ensure colloidal stability in a biological buffer and to transport a variety of therapeutics. However, a major challenge with such inorganic nanostructures is the design of adjustable silica structures, especially with tunable large pores which would be useful, for instance, for the delivery of large therapeutic biomolecule loading and further sustained release. Furthermore, the effect of tailoring a porous silica structure on the magneto- or photothermal dissipation still remains poorly investigated. In this work, we undertake an in-depth investigation of the growth of stellate mesoporous silica (STMS) shells around IO NPs cores and of their micro/mesoporous features respectively through time-lapse and liquid phase transmission electron microscopy (LPTEM) and detailed nitrogen isotherm adsorption studies. We found here that the STMS shell features (thickness, pore size, surface area) can be finely tuned by simply controlling the sol-gel reaction time, affording a novel range of IO@STMS core@shell NPs. Finally, regarding the responses under alternating magnetic fields and NIR light which are evaluated as a function of the silica structure, IO@STMS NPs having a tunable silica shell structure are shown to be efficient as -weighted MRI agents and as heating agents for magneto- and photoinduced hyperthermia. Furthermore, such IO@STMS are found to display anti-cancer effects in pancreatic cancer cells under magnetic fields (both alternating and rotating).
核壳纳米复合材料由氧化铁核（IO NPs）涂覆介孔硅（MS）壳组成，是很有前途的治疗诊断一体化试剂。在交变磁场（AMF）和近红外（NIR）光下，核可作为高效加热纳米试剂，同时作为磁共振成像（MRI）的合适对比剂，而 MS 壳特别有助于确保在生物缓冲液中的胶体稳定性，并输送各种治疗剂。然而，这种无机纳米结构的一个主要挑战是设计可调谐的硅结构，特别是可调谐的大孔，这对于例如输送大的治疗生物分子负载和进一步的持续释放将是有用的。此外，调整多孔硅结构对磁热或光热耗散的影响仍然研究得很少。在这项工作中，我们通过时移和液相透射电子显微镜（LPTEM）以及详细的氮气等温吸附研究，深入研究了 IO NPs 核周围星状介孔硅（STMS）壳的生长及其微/介孔特征。我们发现，通过简单地控制溶胶-凝胶反应时间，可以精细地调整 STMS 壳的特征（厚度、孔径、表面积），从而获得一系列新型的 IO@STMS 核壳 NPs。最后，关于在交变磁场和 NIR 光下的响应，我们评估了作为硅结构函数的响应，结果表明具有可调谐硅壳结构的 IO@STMS NPs 作为加权 MRI 试剂和磁光诱导热疗的加热剂是有效的。此外，在磁场下（交变和旋转），这些 IO@STMS 被发现对胰腺癌细胞具有抗癌作用。
