Interactive threats of nanoparticles to the biological system.

The use of nanoscale materials is growing exponentially, but concerns rise about the human hazards cannot be ignored. Nanotechnology has penetrated deep into our lives in diversified areas as engineering, information technology and diagnostics. Nonetheless owing to their peculiar properties these new materials also present new health risks upon interacting with biological systems. This is a typical case of technology preceding toxicity and therefore, various toxicological aspects for an array of nanomaterials are just beginning to be assessed. Several deleterious effects are being noticed, particularly in vitro situations as well as in mammalian system. Nanoparticles toxicity is compellingly related to oxidative stress, alteration of calcium homeostasis, gene expression, pro-inflammatory responses and cellular signalling events. It is therefore critical to understand the nature and origin of the toxicity imposed by nanomaterials. Keeping all these points in mind, the present review provides updated information on the various aspects such as sources of production, effect of different physical properties, interaction with biological system and mechanisms of engineered nanoparticles induced toxicities.