Alternating current (AC) susceptibility as a particle-focused probe of coating and clustering behaviour in magnetic nanoparticle suspensions.
Alternating current (AC) susceptibility as a particle-focused probe of coating and clustering behaviour in magnetic nanoparticle suspensions.
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DOI：
10.1016/j.jcis.2018.08.014
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发表时间：
2018-12
影响因子：
9.9
通讯作者：
Kaarjel K. Narayanasamy;Melissa Cruz-Acuña;C. Rinaldi;James Everett;J. Dobson;N. Telling
中科院分区：
文献类型：
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作者：
Kaarjel K. Narayanasamy;Melissa Cruz-Acuña;C. Rinaldi;James Everett;J. Dobson;N. Telling
假设磁性纳米颗粒（MNPs）的功能很大程度上依赖于其表面涂层，这反过来又影响了MNPs之间的相互作用，以及单核颗粒或多核簇的形成。在这项研究中，我们评估了交流磁化率（ACS）作为涂覆动力学和功能化纳米颗粒团聚的磁探针的使用。我们利用精氨酸-甘氨酸-天冬氨酸（RGD）三肽结合证明了ACS测量对MNP涂层微小变化的准确性和敏感性，并随后讨论了ACS如何用于优化制备聚乙烯亚胺（PEI）功能化MNP的纳米磁转染应用。实验：我们改变了MNPs悬浮液的PEI负载，表现出布朗松弛和n<s:1>松弛的组合，并使用透析研究了涂层过程中多余PEI的运动。采用ACS数值模拟方法测定了颗粒簇大小和多分散性，并与常规动态光散射（DLS）测量结果进行了比较。sacs提供了MNP涂层和团聚过程的信息，这是DLS无法获得的，因为悬浮液中存在额外的非磁性聚合物颗粒。因此，我们推导出一种简单的方法来获得致密，均匀的PEI涂层，提供高稳定性的悬浮液，而没有过量的未结合PEI。
HypothesisThe functionality of magnetic nanoparticles (MNPs) relies heavily on their surface coating, which in turn affects the interactions between MNPs, and the formation of single-core particles or multi-core clusters. In this study we assessed the use of AC susceptibility (ACS) as a magnetic probe of the kinetics of coating and agglomeration of functionalised nanoparticles. We demonstrate the precision and sensitivity of ACS measurements to small changes in MNP coating using arginine-glycine-aspartic acid (RGD) tripeptide binding, and subsequently discuss how ACS can be used to optimise the preparation of polyethyleneimine (PEI) functionalised MNPs aimed at nanomagnetic transfection applications.ExperimentsWe varied the PEI loading of suspensions of MNPs exhibiting a combination of Brownian and Néel relaxation, and used dialysis to study the movement of excess PEI during the coating process. Numerical ACS simulations were employed to determine particle cluster sizes and polydispersity and the results compared with conventional dynamic light scattering (DLS) size measurements.FindingsACS provided information on the MNP coating and agglomeration process that was not accessible through DLS due to the additional presence of non-magnetic polymer particulates in the suspensions. We consequently derived a simple method to obtain dense, uniform PEI coatings affording high-stability suspensions without excessive quantities of unbound PEI.