Maybe it is because that more nano particals in incubation cells, will bring problem to the swallow and metabolizability of cells, and have an obvious effect on celluar activity and metabolizability;

• 可能是在一定的培养细胞中加入的纳米颗粒过多后，给细胞的内吞和代谢带来了困难，从而对细胞的生命活动和代谢有了明显的影响；