Magnetic resonance imaging (MRI) is a powerful diagnostic technique that can penetrate deep into tissue providing excellent spatial resolution without the need for ionizing radiation or harmful radionuclides. However, diagnosing bacterial infections in vivo with clinical MRI is severely hampered by the lack of contrast agents with high relaxivity, targeting capabilities, and bacterial penetration and specificity. Here, we report the development of the first gadolinium (Gd)-based bacteria-specific targeting MRI contrast agent, probe 1, by conjugating neomycin, an aminoglycoside antibiotic, with Dotarem (Gd-DOTA, an FDA approved T₁-weighted MRI contrast agent). The T₁ relaxivity of probe 1 was found to be comparable to that of Gd-DOTA; additionally, probe 1-treated bacteria generated a significantly brighter T₁-weighted MR signal than Gd-DOTA-treated bacteria. More importantly, in vitro cellular studies and preliminary in vivo MRI demonstrated probe 1 exhibits the ability to efficiently target bacteria over macrophage-like cells, indicating its great potential for high-resolution imaging of bacterial infections in vivo.

中文翻译：

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d标记的氨基糖苷及其作为细菌靶向磁共振成像造影剂的潜在应用

磁共振成像（MRI）是一种强大的诊断技术，可以深入组织内，提供出色的空间分辨率，而无需电离辐射或有害的放射性核素。然而，由于缺乏具有高松驰度，靶向能力以及细菌渗透性和特异性的造影剂，严重阻碍了临床MRI在体内诊断细菌感染。在这里，我们报告了第一种基于ado（Gd ）的细菌特异性靶向MRI造影剂探针1的开发，该方法是将新霉素（一种氨基糖苷类抗生素）与Dotarem（Gd-DOTA，FDA批准的T ₁加权MRI造影剂）结合使用。代理人）。探针1的T ₁弛豫被发现与Gd-DOTA相当；另外，探针1处理的细菌比Gd-DOTA处理的细菌产生明显更亮的T ₁加权MR信号。更重要的是，体外细胞研究和初步的体内MRI证实了探针1能够有效地靶向巨噬细胞样细胞上的细菌，这表明它具有对体内细菌感染进行高分辨率成像的巨大潜力。