Nanomaterial Structural Research Laboratory, Bionanopark Ltd., Lodz, Poland.
Molecular and Nanostructural Biophysics Laboratory, Bionanopark Ltd., Lodz, Poland.
Nanotoxicology. 2022 Apr;16(3):375-392. doi: 10.1080/17435390.2022.2097138. Epub 2022 Jul 10.
The aim of this study is to assess the effect of PAMAM dendrimers of second, fourth, and seventh generations on human umbilical vein endothelial cells. Primary endothelial cells were exposed to PAMAM dendrimers for 24 h, using concentrations reducing cellular viability to the levels of 90, 75, and 50%. We assumed, that changes in mechanical properties reflect toxicity of PAMAM dendrimers. The mechanical properties were investigated using atomic force spectroscopy (AFS) technique with the use of two approaches for measuring cell elasticity: global, where the tests were performed using a micrometer-hemispherical probe, and local, where a nanometer-sized probe was used. For the sharp probe, a reduction in the elasticity modulus was observed in comparison to untreated control cells, that is related to the depolymerization of the cytoskeleton and the processes leading to cell apoptosis. In the case of the hemispherical probe, cell softening was also observed in comparison to control cells, but with increasing PAMAM concentrations, the modulus of elasticity increases. It is related to the sensing of numerous intracellular vesicles with the use of this probe, e.g. endosomal and empty plasmalemmal which can also alter cell elasticity. The presence of external and intracellular vesicles was confirmed by scanning and transmission electron microscopy. The relationship between the elasticity of HUVEC cells exposed to PAMAM dendrimers of selected generations and their toxic effects was presented herein for the first time. In the transmission electron microscopy images of the cells exposed to PAMAM dendrimers, we have also observed distinctive vesicles with regular multilayer arranged structure.
本研究旨在评估第二代、第四代和第七代聚酰胺-胺树枝状聚合物对人脐静脉内皮细胞的影响。原代内皮细胞用聚酰胺-胺树枝状聚合物孵育 24 小时，使用浓度将细胞活力降低至 90%、75%和 50%。我们假设，力学性质的变化反映了聚酰胺-胺树枝状聚合物的毒性。使用原子力光谱（AFS）技术，通过两种方法测量细胞弹性来研究力学性质：全局法，使用微米半球探针进行测试；局部法，使用纳米探针进行测试。对于尖锐探针，与未处理的对照细胞相比，弹性模量降低，这与细胞骨架的解聚和导致细胞凋亡的过程有关。对于半球探针，与对照细胞相比，也观察到细胞软化，但随着聚酰胺-胺浓度的增加，弹性模量增加。这与使用该探针感知大量细胞内囊泡有关，例如内体和空质膜，这也可以改变细胞的弹性。通过扫描和透射电子显微镜证实了细胞内和细胞外囊泡的存在。本文首次提出了暴露于选定代聚酰胺-胺树枝状聚合物的 HUVEC 细胞的弹性与其毒性效应之间的关系。在暴露于聚酰胺-胺树枝状聚合物的细胞的透射电子显微镜图像中，我们还观察到具有规则多层排列结构的独特囊泡。
