Applying ferrite nanobeads to medical diagnosis, therapy and analysis

采用共沉淀法、部分氧化法和晶种生长法成功制备了尺寸可控的10-100 nm铁氧体纳米粒子。功能聚合物包覆铁氧体纳米棒的研制通过共聚和新型无皂聚合的方法，成功地在铁-铁氧体纳米粒子表面包覆了聚甲基丙烯酸甲酯，这种聚合物对蛋白质的非特异性吸附最小。聚合物包覆铁纳米棒的研究成功地在金属铁纳米粒子(尺寸为7-20 nm)上包覆了聚甲基丙烯酸甲酯，这种纳米粒子的磁化强度是铁氧体粒子的两倍，有利于生物筛选中的磁分离。聚甲基丙烯酸甲酯包覆的铁氧体纳米棒与抗癌抗体和含有标记蛋白…的重组蛋白等生理活性物质的偶联更多In-G利用珠子，我们成功地捕获了与结合在珠子上的物质相辅相成的生理活性物质。这表明我们的珠子适合用于高通量生物筛选的磁性载体。在霍尔生物传感诊断中的应用将包被聚甲基丙烯酸甲酯的铁氧体纳米棒与单链DNA偶联，通过杂交将其固定在霍尔传感器表面，并将互补DNA单链固定在传感器表面。这表明我们的珠子适用于磁性载体进行DNA分析。对比增强磁共振成像在诊断中的应用我们成功地用多种功能分子对铁氧体纳米棒进行了表面修饰，发现了高性能磁共振造影剂的候选材料。在抗癌磁热治疗中的应用利用铁氧体纳米棒作为热源，在120 kHz的无创频率下进行磁场感应，成功地杀死了人结肠癌细胞。从而揭示了我们的微珠适用于无创、抗癌的磁热治疗的磁性载体。较少

1. Development of size controlled ferrite nanobeadsIron-ferrite nanoparticles with controlled size of 10-100 nm were successfully synthesized by our newly developed methods called co-precipitation, partial-oxidation, and seed-growth methods.2. Development of functional-polymer coated ferrite nanobeadsThe iron-ferrite nanoparticles were successfully coated with poly-GMA, which exhibits minimal non-specific adsorption of proteins, by a co-polymerization method and a novel, soap-free polymerization method.3. Development of polymer coated iron nanobeadsMetallic iron nanoparticles (7-20 nm in size), which have magnetization two times stronger than that of ferrite particles and are advantageous for magnetic separation in bio-screening, were successfully coated with poly-GMA.4. Application to analysis by bio-screening systemThe poly-GMA coated ferrite nanobeads were conjugated with physiologically active substances such as anticancer antibodies and recombinant proteins containing tagged Prote … More in-G. Utilizing the beads, we successfully captured physiologically active substances that are complementary to those conjugated onto the beads. This revealed our beads are fitted for magnetic carriers for high throughput bio-screening.5. Application to diagnosis by Hall bio-sensingpoly-GMA coated ferrite nanobeads were conjugated with single strand DNA, which were immobilized onto the surface of a Hall sensor via hybridization with the complementary DNA single strand fixed on the sensor surface. This revealed our beads are applicable to magnetic carriers for DNA analysis.6. Application to diagnosis by contrast enhanced MRIWe successfully modified the surfaces of the ferrite nanobeads with a variety of functional molecules, and discovered candidate materials for high performance MRI contrast agent.7. Application to anticancer magnetic hyperthermiaUtilizing the ferrite nanobeads as heat source by magnetic-field induction at an non-invasive frequency of 120 kHz, we successfully killed human colon cancer cells. We thus revealed that our beads are applicable to magnetic carriers for non-invasive, anticancer magnetic hyperthermia. Less