Shaped Magnetogel Microparticles for Multispectral Magnetic Resonance Contrast and Sensing
Shaped Magnetogel Microparticles for Multispectral Magnetic Resonance Contrast and Sensing
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DOI：
10.1021/acssensors.3c01373
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发表时间：
2023-12-19
期刊：
影响因子：
8.9
通讯作者：
Zabow，Gary
中科院分区：
文献类型：
--
作者：
Oberdick，Samuel D.;Dodd，Stephen J.;Zabow，Gary
多光谱磁共振成像 (MRI) 造影剂是微加工的三维磁性结构，可以用离散频率对附近的水质子进行编码。这些试剂具有独特的射频 (RF) 共振，可以通过设计这些微结构的几何参数来调节。通过将刺激驱动的形状变化响应纳入其结构中，多光谱造影剂可以用作传感器。这些几何编码磁传感器 (GEMS) 通过环境引起的几何形状变化及其相应的射频共振，实现基于 MRI 的传感。此前，GEMS 是在洁净室环境中使用薄膜光刻技术制造的。虽然这些方法可以精确控制微观结构，但对于没有洁净室或微加工专业知识的研究人员来说，它们可能是一种限制。这里介绍了一种基于软光刻的 GEMS 制造替代方法。该制造方案使用廉价、易获得的材料和简单的化学方法来生产具有多光谱 MRI 对比特性的成形磁性水凝胶微粒。通过将微粒制成形状可重构的“智能”水凝胶，可以将其用作传感器。形状的变化会导致 GEMS 共振发生相应的变化，从而产生微环境的 MRI 可寻址读数。原理验证实验显示了圆柱壳状磁凝胶 GEMS 对 pH 变化的多光谱响应。
Multispectral magnetic resonance imaging (MRI) contrast agents are microfabricated three-dimensional magnetic structures that encode nearby water protons with discrete frequencies. The agents have a unique radiofrequency (RF) resonance that can be tuned by engineering the geometric parameters of these microstructures. Multispectral contrast agents can be used as sensors by incorporating a stimulus-driven shape-changing response into their structure. These geometrically encoded magnetic sensors (GEMS) enable MRI-based sensing via environmentally induced changes to their geometry and their corresponding RF resonance. Previously, GEMS have been made using thin-film lithography techniques in a cleanroom environment. While these approaches offer precise control of the microstructure, they can be a limitation for researchers who do not have cleanroom access or microfabrication expertise. Here, an alternative approach for GEMS fabrication based on soft lithography is introduced. The fabrication scheme uses cheap, accessible materials and simple chemistry to produce shaped magnetic hydrogel microparticles with multispectral MRI contrast properties. The microparticles can be used as sensors by fabricating them out of shape-reconfigurable, “smart” hydrogels. The change in shape causes a corresponding shift in the resonance of the GEMS, producing an MRI-addressable readout of the microenvironment. Proof-of-principle experiments showing a multispectral response to pH change with cylindrical shell-shaped magnetogel GEMS are presented.