NANOPARTICLES OF MAGNETIC IRON OXIDES AS PROSPECTIVE DIAGNOSTIC AGENTS

这个子项目是利用资源的许多研究子项目之一。 由NIH/NCRR资助的中心拨款提供。对子项目的主要支持 子项目的首席调查员可能是由其他来源提供的， 包括美国国立卫生研究院的其他来源。为子项目列出的总成本可能 表示该子项目使用的中心基础设施的估计数量， 不是由NCRR赠款提供给次级项目或次级项目工作人员的直接资金。 本项目的目标是获得新型超小型氧化铁基磁性材料。 嵌入非聚合物生物相容有机壳中的颗粒具有可变的 并测试它们作为预期的细胞标记和磁共振造影剂用于 癌症和其他疾病诊断学。我们假设小分子封顶 覆盖在粒子表面的配体将为 潜在的标记剂，当与聚合物覆盖的颗粒比较时。我们还有 改变有机壳的分子结构和厚度的假说 可以帮助改变质子弛豫的机制，这是 不同的核磁共振应用。所获得的材料可以很好地替代 目前使用的是有毒的Gd造影剂。我们建议：(A)合成 磁铁矿和/或磁铁矿的纳米颗粒，核心尺寸为2-4 并对其结构和磁性进行了研究。这将由HIGH- 无表面活性剂条件下螯合铁(II)和(III)络合物的温度水解 齐次解。(B)使合成的纳米晶与各种 ···研究了分子结构的影响 纳米晶-配体界面对纳米粒子胶体结构和稳定性的影响。 (C)优化复合粒子的设计，作为潜在的细胞标记和核磁共振 造影剂。这将通过改变纳米晶体的结构来解决- 通过改变晶核与有机壳层大小的比例，实现了有机壳层界面的优化。这个 界面的结构(内球)将通过改变配体来控制 纳米晶的覆盖和配体分子结构的改变 我的脊梁。颗粒尺寸将通过改变纳米晶尺寸和 形成外球的封端配体侧取代基的几何构型 纳米颗粒的含量。 合成的磁性材料将被提供给生物研究设施 用于评估它们的细胞毒性，并到放射设备研究它们的松弛性能 属性。

This subproject is one of many research subprojects utilizing the resources provided by a Center grant funded by NIH/NCRR. Primary support for the subproject and the subproject's principal investigator may have been provided by other sources, including other NIH sources. The Total Cost listed for the subproject likely represents the estimated amount of Center infrastructure utilized by the subproject, not direct funding provided by the NCRR grant to the subproject or subproject staff. The goal of this project is to obtain new ultrasmall iron oxide-based magnetic particles embedded in a nonpolymeric biocompatible organic shell with variable coverage and to test them as prospective cell labeling and MRI contrast agents for cancer and other diseases diagnostics. We hypothesize that small-molecule capping ligands covering the particles' surface will provide greater mobility and diffusion for a potential labeling agent when compared to polymer-covered particles. We also have a hypothesis that varying the molecular structure and thickness of the organic shell can help with changing the mechanism of the proton relaxation which is needed for different MRI applications. The obtained materials can be good alternatives to currently used toxic gadolinium contrast agents. We are proposing: (a) To synthesize the nanoparticles of magnetite and/or maghemite, with the core dimensions of 2-4 nm, and to study their structure and magnetic properties. This will be done by high- temperature hydrolysis of chelated iron (II) and (III) complexes in surfactant-free homogeneous solutions. (b) To react the synthesized nanocrystals with various hydroxycarboxylic acids and to study the influence of the molecular structure at the nanocrystal-ligand interface on structure and stability of the nanoparticles' colloids. (c) To optimize the design of the composite particles as potential cell labeling and MRI contrast agents. This will be addressed by changing the structure of the nanocrystal- organic shell interface and by changing the crystal core to organic shell size ratio. The structure of the interface (inner sphere) will be controlled by changing the ligand coverage of the nanocrystals and changing the molecular structure of the ligands' backbone. Particle dimensions will be adjusted by varying the nanocrystal size and the geometry of the capping ligand's side substituent which forms the outer sphere of the nanoparticle. The synthesized magnetic materials will be provided to biological research facilities for evaluation of their cytotoxicity and to radiology facilities to study their relaxivity properties.