Daou T J, Pourroy G, Greneche J M, Bertin A, Felder-Flesch D, Begin-Colin S
Institut de Physique et Chimie des Matériaux, UMR 7504 CNRS-Université de Strasbourg, 23 rue du Loess, BP 43, 67034, Strasbourg Cedex 2, France.
Dalton Trans. 2009 Jun 21(23):4442-9. doi: 10.1039/b823187g. Epub 2009 Apr 9.
The grafting of pegylated dendrons on 9(2) nm and 39(5) nm iron oxide nanoparticles in water, through a phosphonate group as coupling agent has been successfully achieved and its mechanism investigated, with a view to produce biocompatible magnetic nano-objects for biomedical applications. Grafting has been demonstrated to occur by interaction of negatively charged phosphonate groups with positively charged groups and hydroxyl at the iron oxide surface. The isoelectric point of the suspension of dendronized iron oxide nanoparticles is shifted towards lower pH as the amount of dendron increases. It reaches 4.7 for the higher grafting rate and for both particle size. Thus, the grafting of molecules using a phosphonate group allows stabilizing electrostatically the suspensions at physiological pH, a prerequisite for biomedical applications. Moreover the grafting step has been shown to preserve the magnetic properties of iron oxide nanoparticles due to super-super exchange interactions through the phosphonate group.
通过膦酸酯基团作为偶联剂，已成功实现了在水中将聚乙二醇化树枝状分子接枝到9(2)纳米和39(5)纳米的氧化铁纳米颗粒上，并对其机理进行了研究，目的是制备用于生物医学应用的生物相容性磁性纳米物体。已证明接枝是通过带负电荷的膦酸酯基团与氧化铁表面带正电荷的基团和羟基相互作用而发生的。随着树枝状分子数量的增加，树枝状氧化铁纳米颗粒悬浮液的等电点向较低pH值移动。对于较高的接枝率和两种粒径，其等电点均达到4.7。因此，使用膦酸酯基团接枝分子可在生理pH值下静电稳定悬浮液，这是生物医学应用的一个先决条件。此外，接枝步骤已表明由于通过膦酸酯基团的超超交换相互作用，可保留氧化铁纳米颗粒的磁性。
