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。子项目的主要支持 而子项目的主要调查员可能是由其他来源提供的， 包括其它NIH来源。 列出的子项目总成本可能 代表子项目使用的中心基础设施的估计数量， NCRR赠款不直接向子项目或子项目工作人员提供资金。 该项目的目标是获得新的超小氧化铁基磁性 嵌入非聚合物生物相容性有机壳中的颗粒， 覆盖范围，并测试它们作为前瞻性细胞标记和MRI造影剂， 癌症和其他疾病的诊断。我们假设小分子封盖 覆盖颗粒表面的配体将为纳米颗粒提供更大的移动性和扩散性。 当与聚合物覆盖的颗粒相比时是潜在的标记剂。我们也有 一个假设，改变分子结构和厚度的有机壳 可以帮助改变质子弛豫的机制， 不同的MRI应用。所获得的材料可以是良好的替代品， 目前使用的有毒钆造影剂。我们建议：（a）综合 磁铁矿和/或磁赤铁矿的纳米颗粒，其核尺寸为2-4 nm，并对其结构和磁性进行了研究。这将由高- 螯合的铁（II）和（III）络合物在无表面活性剂中的温度水解 齐次解(b)为了使合成的纳米晶体与各种 羟基羧酸和研究的影响，分子结构在 纳米颗粒-配体界面对纳米颗粒胶体的结构和稳定性的影响。 (c)为了优化作为潜在的细胞标记和MRI的复合颗粒的设计 造影剂。这将通过改变组织结构来解决。 有机壳界面和通过改变晶体核与有机壳的尺寸比。的 通过改变配位体，可以控制界面（内球）的结构 纳米晶体的覆盖和改变配体的分子结构 骨干粒子尺寸将通过改变粒子大小进行调整， 形成外层的封端配体侧取代基的几何形状 的纳米粒子。 合成的磁性材料将提供给生物研究设施 用于评价其细胞毒性，并用于放射学设施以研究其弛豫性 特性.

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.