Chistè Elena, Ischia Gloria, Gerosa Marco, Marzola Pasquina, Scarpa Marina, Daldosso Nicola
Department of Computer Science, Fluorescence Laboratory, University of Verona, 37134 Verona, Italy.
Department of Industrial Engineering, University of Trento, 38123 Trento, Italy.
Nanomaterials (Basel). 2020 Mar 4;10(3):463. doi: 10.3390/nano10030463.
Porous silicon (pSi) microparticles obtained by porosification of crystalline silicon wafers have unique optical properties that, together with biodegradability, biocompatibility and absence of immunogenicity, are fundamental characteristics to candidate them as tracers in optical imaging techniques and as drug carriers. In this work, we focus on the possibility to track down the pSi microparticles also by MRI (magnetic resonance imaging), thus realizing a comprehensive tool for theranostic applications, i.e., the combination of therapy and diagnostics. We have developed and tested an easy, quick and low-cost protocol to infiltrate the COOH-functionalized pSi microparticles pores (tens of nanometers about) with magnetic nanospheres (SPIONs-Super Paramagnetic Iron Oxide Nanoparticles, about 5-7 nm) and allow an electrostatic interaction. The structural properties and the elemental composition were investigated by electron microscopy techniques coupled to elemental analysis to demonstrate the effective attachment of the SPIONs along the pores' surface of the pSi microparticles. The magnetic properties were investigated under an external magnetic field to determine the relaxivity properties of the material and resulting in an alteration of the relaxivity of water due to the SPIONs presence, clearly demonstrating the effectiveness of the easy functionalization protocol proposed.
通过对晶体硅片进行多孔化处理得到的多孔硅（pSi）微粒具有独特的光学特性，这些特性连同生物可降解性、生物相容性和无免疫原性一起，是使其成为光学成像技术中的示踪剂和药物载体的基本特征。在这项工作中，我们专注于通过磁共振成像（MRI）追踪pSi微粒的可能性，从而实现一种用于治疗诊断应用的综合工具，即治疗与诊断的结合。我们开发并测试了一种简单、快速且低成本的方案，用磁性纳米球（超顺磁性氧化铁纳米颗粒，约5 - 7纳米）渗透COOH功能化的pSi微粒的孔隙（约几十纳米），并实现静电相互作用。通过与元素分析相结合的电子显微镜技术研究了结构特性和元素组成，以证明超顺磁性氧化铁纳米颗粒沿pSi微粒孔隙表面的有效附着。在外部磁场下研究了磁性特性，以确定材料的弛豫特性，结果表明由于超顺磁性氧化铁纳米颗粒的存在，水的弛豫率发生了变化，清楚地证明了所提出的简单功能化方案的有效性。
