Kettering Melanie, Zorn Heike, Bremer-Streck Sibylle, Oehring Hartmut, Zeisberger Matthias, Bergemann Christian, Hergt Rudolf, Halbhuber Karl-Jürgen, Kaiser Werner A, Hilger Ingrid
Institute of Diagnostic and Interventional Radiology, University Hospital Jena, Erlanger Allee 101, 07747 Jena, Germany.
Phys Med Biol. 2009 Sep 7;54(17):5109-21. doi: 10.1088/0031-9155/54/17/003. Epub 2009 Aug 6.
The aim of this study was to characterize the behaviour of cisplatin adsorbed magnetic nanoparticles (cis-MNPs) for minimal invasive cancer treatments in preliminary in vitro investigations. Cisplatin was adsorbed to magnetic nanoparticles (MNPs) by simple incubation. For stability determinations, cis-MNPs were incubated in dH(2)O, phosphate-buffered saline (PBS) and fetal calf serum (FCS) at 4-121 degrees C up to 20 weeks. Hydrodynamic diameters were measured using laser diffraction. The extent of cisplatin linkage was determined by atomic absorption spectrometry. The magnetite core size was assessed by vibrating sample magnetometry and transmission electron microscopy. The specific loss power (SLP) was measured in an alternating magnetic field. Our results showed that a maximum of 10.3 +/- 1.6 (dH(2)O), 10 +/- 1.6 (PBS) and 13.4 +/- 2.2 (FCS) mg cisplatin g(-1) Fe could be adsorbed to MNPs. With hyperthermal (42 degrees C) or thermal ablative (60 degrees C) temperatures, used for therapeutic approaches, cisplatin did not desorb from cis-MNPs in dH(2)O during incubation times of 180 or 30 min, respectively. In PBS and FCS, cisplatin amounts adsorbed to MNPs decreased rapidly to approximately 50% and 25% at these temperatures. This cisplatin release will be necessary for successful chemotherapeutic activity and should increase the therapeutic effect of magnetic heating treatment in medicinal applications. The hydrodynamic diameters of MNPs or cis-MNPs were around 70 nm and magnetization data showed superparamagnetic behaviour. The obtained mean core diameter was around 12 nm. The SLP of the sample was calculated to be 75.5 +/- 1.6 W g(-1). In conclusion, cis-MNPs exhibit advantageous features for a facilitated desorption of cisplatin in biological media and the heating potential is adequate for hyperthermic treatments. Therefore, even though further detailed investigations are still necessary, tentative use in local tumour therapies aiming at a specific chemotherapeutic release in combination with magnetic heating seems to be feasible in the long term.
本研究的目的是在初步体外研究中表征顺铂吸附磁性纳米颗粒（顺铂-MNP）在微创癌症治疗中的行为。通过简单孵育将顺铂吸附到磁性纳米颗粒（MNP）上。为了进行稳定性测定，将顺铂-MNP在4-121℃的去离子水（dH₂O）、磷酸盐缓冲盐水（PBS）和胎牛血清（FCS）中孵育长达20周。使用激光衍射测量流体动力学直径。通过原子吸收光谱法测定顺铂连接的程度。通过振动样品磁强计和透射电子显微镜评估磁铁矿核心尺寸。在交变磁场中测量比损耗功率（SLP）。我们的结果表明，MNP最多可吸附10.3±1.6（dH₂O）、10±1.6（PBS）和13.4±2.2（FCS）mg顺铂/g Fe。在用于治疗方法的高温（42℃）或热消融（60℃）温度下，在180分钟或30分钟的孵育时间内，顺铂在dH₂O中未从顺铂-MNP上解吸。在这些温度下，在PBS和FCS中，吸附到MNP上的顺铂量分别迅速降至约50%和25%。这种顺铂释放对于成功的化疗活性是必要的，并且应该会增加磁热治疗在医学应用中的治疗效果。MNP或顺铂-MNP的流体动力学直径约为70nm，磁化数据显示出超顺磁行为。获得的平均核心直径约为12nm。样品的SLP计算为75.5±1.6W/g。总之，顺铂-MNP在促进顺铂在生物介质中的解吸方面表现出有利特性，并且加热潜力足以用于热疗。因此，尽管仍需要进一步详细研究，但从长远来看，尝试用于旨在结合磁热进行特定化疗释放的局部肿瘤治疗似乎是可行的。
