Pakravanan Kimiya, Bazzurro Virginia, Salerno Marco, Diaspro Alberto
Dipartimento di Fisica, Università di Genova, Genoa, Italy.
Nanoscopy and NIC@IIT, CHT, Istituto Italiano di Tecnologia, Genoa, Italy.
Eur Biophys J. 2025 Jun 19. doi: 10.1007/s00249-025-01769-5.
Uptake of gold nanoparticles by HeLa cells fixed at different incubation times of up to eight hours was investigated using 3D confocal laser scanning microscopy followed by image analysis. The cell bodies were characterized by fluorescence labeling, whereas the gold nanoparticles were identified by light scattering. The amount of nanoparticles uptaken at different times was evaluated with Fiji according to a dedicated protocol. We assessed the effect of particle size (80 and 150 nm diameter spheres) and shape (spheres vs "urchins") on their uptake. The large spherical nanoparticles presented approximately fourfold higher levels of uptake than the nanourchins. Also, the spheres presented a clearly increasing uptake in the time profile, reaching a maximum around seven hours and then showing a slight decrease. We ascribe this behavior to a lower aptitude of the cells for taking up nanoparticles with either urchin shape or smaller size and to the possible presence of competing kinetics for exocytosis at the longest times. Live experiments confirmed for the time profile a relatively flat cell response to the urchins and an increasing response to the spheres, yet with a final plateau. However, in the live case, the internalization levels were as low for the spheres as for the urchins.
使用三维共聚焦激光扫描显微镜并结合图像分析，研究了在长达八小时的不同孵育时间下固定的HeLa细胞对金纳米颗粒的摄取情况。细胞体通过荧光标记进行表征，而金纳米颗粒则通过光散射进行识别。根据专门的方案，使用Fiji评估不同时间摄取的纳米颗粒数量。我们评估了颗粒大小（直径80和150纳米的球体）和形状（球体与“海胆”）对其摄取的影响。大型球形纳米颗粒的摄取水平比纳米海胆高出约四倍。此外，球体在时间曲线上呈现出明显增加的摄取，在大约七小时时达到最大值，然后略有下降。我们将这种行为归因于细胞摄取海胆形状或较小尺寸纳米颗粒的能力较低，以及在最长时间可能存在的胞吐竞争动力学。实时实验证实了时间曲线，细胞对海胆的反应相对平稳，对球体的反应不断增加，但最终达到平稳状态。然而，在实时情况下，球体的内化水平与海胆一样低。
