Hello Dr Heba

The agent could inhibit functional protein. You have to double check the mechanism of cell death for that agent.

Did you test the nanoparticle alone without the agent?

The Best

Abdo

the used agent is a nanoparticle (alone)

Hello Heba.

When we consider progress of cell damages leading to cell dying or cell death, the gradual process would be intracellular accumulation of ROS through non-genetic or genetic causes. Two suggestions!!!

1) The toxic load is high enough to abolish by cell itself, then the cell undergoes various cytotoxic pressure. I recommend to first determine the level of the nanoparticles to cause intracelluar ROS accumulation in a manner of IC50. Then seek the leves of the nanoparticle toxicity. The level of the nanopartices you found may be far too high for the cell to respond gradual ROS accumulation within the cell. It caused a kind of sudden death, which is so different from the biological cell death. The threshold of the nanoparticle concentration causing cell death may be too high for the cell to show any ROS accumulation. Just like boiling cells at hot temeperature rather than gradual increasing temperature.

2) The reason for no ROS accumulation could be two-folds. One may be the toxicity of the nanoparticles themselves. The other would be the toxicity of the remaining toxic chemicals used for preparation of nanoparticles or the remaining carrier solution as a form of added to the culture. If you are suspecting this, wash the particles with several times by spinning with culture medium before addition.

Best wishes.