Department of Chemistry, Purdue University, West Lafayette, IN 47907, USA.
Molecules. 2023 Mar 26;28(7):2953. doi: 10.3390/molecules28072953.
Magnetic resonance imaging (MRI) is a medical imaging technique that provides detailed information on tissues and organs. However, the low sensitivity of the technique requires the use of contrast agents, usually ones that are based on the chelates of gadolinium ions. In an effort to improve MRI signal intensity, we developed two strategies whereby the ligand DOTA and Gd(III) ions are contained within Zn(II)-promoted collagen peptide () supramolecular assemblies. The DOTA moiety was included in the assembly either via a collagen peptide sidechain () or through metal-ligand interactions with a His-tagged DOTA conjugate (). SEM verified that the morphology of the assembly was maintained in the presence of the DOTA-containing peptides (microflorettes), and EDX and ICP-MS confirmed that Gd(III) ions were incorporated within the microflorettes. The Gd(III)-loaded DOTA florettes demonstrated higher intensities for the T1-weighted MRI signal and higher longitudinal relaxivity (r) values, as compared to the clinically used contrast agent Magnevist. Additionally, no appreciable cellular toxicity was observed with the collagen microflorettes loaded with Gd(III). Overall, two peptide-based materials were generated that have potential as MRI contrast agents.
磁共振成像(MRI)是一种提供组织和器官详细信息的医学成像技术。然而,该技术的低灵敏度需要使用造影剂,通常是基于镧系离子螯合物的造影剂。为了提高 MRI 信号强度,我们开发了两种策略,将配体 DOTA 和 Gd(III)离子包含在 Zn(II)促进的胶原肽 ()超分子组装体中。DOTA 部分通过胶原肽侧链()或通过与带有 His 标签的 DOTA 缀合物()的金属配体相互作用包含在组装体中。SEM 证实,在含有 DOTA 的肽(微花束)存在下,组装体的形态得以维持,并且 EDX 和 ICP-MS 证实 Gd(III)离子包含在微花束中。与临床上使用的造影剂 Magnevist 相比,负载 Gd(III)的 DOTA 花束表现出更高的 T1 加权 MRI 信号强度和更高的纵向弛豫率(r)值。此外,负载 Gd(III)的胶原微花束没有观察到明显的细胞毒性。总的来说,生成了两种基于肽的材料,它们具有作为 MRI 造影剂的潜力。