Abstract

The factors that affect the labeling of NIH 3T3 murine fibroblasts with Fe₃O₄-based magnetic nanoparticles (MNPs) were studied using MNPs produced by the gas condensation and solution precipitation methods and MNPs surface-modified with 3-aminopropylsilane or L-lysine. The production method, surface modifications, the particle concentration and size, the state of the cell population, and the method of MNP introduction were found to substantially affect the efficiency of MNP binding by cells. In particular, large MNP clusters may occur in MNP suspensions in DMSO, and their disruption by sonication increased the percent yield of magnetically labeled cells. Static incubation of a cell suspension led to a more efficient labeling as compared with continuous agitation. Cells attached to a plastic support could be labeled to a higher degree than cells in suspension, but required substantially longer incubations with MNPs. MNP centrifugation on cell layers (magnetic spinoculation) significantly increased the rate and efficiency of labeling. The stability of magnetic labeling was shown to depend on the MNP dose during labeling. Electron microscopy studies demonstrated that MNPs were associated with the cell surface after 20-min incubation with cells and were mostly in the cell interior after 4-h incubation. The results of the study may be useful for preparation and application of magnetized cell samples.

中文翻译：

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影响磁性纳米粒子标记NIH 3T3细胞的因素

摘要

Fe ₃ O ₄标记NIH 3T3鼠成纤维细胞的因素使用通过气体缩合和溶液沉淀法生产的MNP，以及经3-氨丙基硅烷或L-赖氨酸表面改性的MNP，研究了基于MNPs的磁性纳米颗粒（MNP）。发现生产方法，表面修饰，颗粒浓度和大小，细胞群的状态以及MNP引入方法实质上影响细胞与MNP结合的效率。特别是，大的MNP簇可能会出现在DMSO的MNP悬浮液中，并且通过超声处理对其进行破坏会增加磁性标记细胞的百分产率。与连续搅拌相比，细胞悬液的静态温育导致更有效的标记。与悬浮液中的细胞相比，附着在塑料支持物上的细胞可以被标记得更高，但是需要与MNPs进行更长的孵育时间。细胞层上的MNP离心（磁性自旋接种）显着提高了标记的速度和效率。磁性标记的稳定性被证明取决于标记期间的MNP剂量。电子显微镜研究表明，与细胞孵育20分钟后，MNPs与细胞表面相关，并且在孵育4h后大部分位于细胞内部。研究结果可能对磁化细胞样品的制备和应用有用。电子显微镜研究表明，与细胞孵育20分钟后，MNPs与细胞表面相关，并且在孵育4h后大部分位于细胞内部。研究结果可能对磁化细胞样品的制备和应用有用。电子显微镜研究表明，与细胞孵育20分钟后，MNPs与细胞表面相关，并且在孵育4h后大部分位于细胞内部。研究结果可能对磁化细胞样品的制备和应用有用。