Wiekhorst F, Seliger C, Jurgons R, Steinhoff U, Eberbeck D, Trahms L, Alexiou C
Department of Otorhinolaryngology, Head and Neck Surgery, University Erlangen-Nürnberg, Germany.
J Nanosci Nanotechnol. 2006 Sep-Oct;6(9-10):3222-5. doi: 10.1166/jnn.2006.477.
Magnetic nanoparticles can be used in medicine in vivo as contrast agents and as a drug carrier system for chemotherapeutics. Thus local cancer therapy is performed with Magnetic Drug Targeting (MDT) and allows a specific delivery of therapeutic agents to desired targets, i.e., tumors, by using a chemotherapeutic substance bound to magnetic nanoparticles and focused with an external magnetic field to the tumor after intraarterial application. Important for this therapeutic principle is the distribution of the particles in the whole organism and especially in the tumor. Therefore we used magnetorelaxometry to quantify ferrofluids delivered after MDT. Tissue samples of some mm3 volume of a VX2 squamous cell carcinoma were measured by magnetic relaxation and the amount of iron was determined using the original ferrofluid suspension as a reference. From this the distribution of the magnetic particles within the slice of tumor was reconstructed. Histological cross-sections of the respective tumor offer the opportunity to map quantitatively the particle distribution and the vascularisation in the targeted tumor on a microscopic scale. Our data show that the integral method magnetorelaxometry and microscopic histological methods can complete each other efficiently.
磁性纳米颗粒可在体内医学中用作造影剂和化疗药物载体系统。因此，通过磁性药物靶向（MDT）进行局部癌症治疗，在动脉内应用后，利用与磁性纳米颗粒结合的化疗物质并通过外部磁场将其聚焦到肿瘤上，从而实现治疗剂向所需靶点（即肿瘤）的特异性递送。对于这一治疗原理而言，颗粒在整个生物体尤其是肿瘤中的分布至关重要。因此，我们使用磁弛豫测量法对MDT后递送的铁磁流体进行定量。通过磁弛豫测量VX2鳞状细胞癌几立方毫米体积的组织样本，并以原始铁磁流体悬浮液为参考确定铁含量。由此重建了肿瘤切片内磁性颗粒的分布。相应肿瘤的组织学横截面提供了在微观尺度上定量绘制靶向肿瘤中颗粒分布和血管化情况的机会。我们的数据表明，积分法磁弛豫测量和微观组织学方法可以有效地相互补充。
