Materials Engineering, Indian Institute of Technology Gandhinagar, Gujarat, India.
Colorado Center for Nanomedicine and Nanosafety, Skaggs School of Pharmacy and Pharmaceutical Sciences, University of Colorado Anschutz Medical Campus, Aurora, CO, USA.
NanoImpact. 2021 Apr;22:100324. doi: 10.1016/j.impact.2021.100324. Epub 2021 May 15.
Nanoparticles under a reactive microenvironment, have the propensity to undergo morphological and compositional changes, which can translate into band edge widening. Although cell membrane depolarization has been linked with the electronic band structure of nanomaterials in their native state, the change in band structure as a consequence of a soluble nanoparticle system is less studied. Therefore we studied the consequence of dissolution of CuO nanoparticles on the band structure and flat band potentials and correlated it with its ability to induce a intracellular oxidative stress. The temporal variation in bandgap, fermi energy level and valence band maxima were evaluated on the remnant CuO nanoparticles post dissolution. CuO nanoparticles showed a very high dissolution in simulated body fluid (51%) and cell culture media (75%). This dissolution resulted in an physico-chemical transformation of CuO nanoparticles. A temporal increase in the bandgap energy as a result of media interaction was up to 107%. Temporal variation in the flat band potentials with the generation of intracellular ROS, cell viability, late and early apoptosis in addition to necrosis on RAW 264.7 cells was established due to biological redox potential overlap. The mRNA expression for TNF-α, IL-6, IL-1β and IL-10 in response to the particle treatment was also evalulated for 6 hours. Through this study, we establish that the toxicological potential of CuO nanoparticles is a temporal function of band energies (its overlap with the intracellular redox potential) followed by release of ionic species in the cytotoxic regime.
在反应性微环境下，纳米颗粒倾向于发生形态和组成变化，这可能导致能带边缘变宽。虽然细胞膜去极化与纳米材料在其天然状态下的电子能带结构有关，但可溶性纳米颗粒体系中能带结构的变化研究较少。因此，我们研究了 CuO 纳米颗粒溶解对能带结构和平带电位的影响，并将其与诱导细胞内氧化应激的能力相关联。在溶解后剩余的 CuO 纳米颗粒上评估了带隙、费米能级和价带最大值的时间变化。CuO 纳米颗粒在模拟体液（51%）和细胞培养基（75%）中表现出非常高的溶解度。这种溶解导致了 CuO 纳米颗粒的物理化学转化。由于介质相互作用，能带隙能量在时间上增加了 107%。由于生物氧化还原电位重叠，在 RAW 264.7 细胞中产生的细胞内 ROS、细胞活力、晚期和早期细胞凋亡以及坏死，以及平带电位的时间变化得以确定。还针对 TNF-α、IL-6、IL-1β 和 IL-10 的 mRNA 表达进行了 6 小时的评估。通过这项研究，我们确定 CuO 纳米颗粒的毒理学潜力是能带能量的时间函数（其与细胞内氧化还原电位的重叠），随后在细胞毒性范围内释放离子物种。
