Nanotechnology, like genetically modified food or nuclear power, often produces a knee-jerk reaction. It’s somehow ‘not natural’ and so is considered scary and dangerous. This is primarily a reaction to words, the same way that it easy for advertisers to push emotional buttons with ‘natural’ as good and ‘artificial’ as bad.
This is a silly distinction. There is a lot in nature that is very dangerous indeed – and much that is artificial protects us from that. If you doubt this, try removing everything artificial when you are flying in a plane over shark infested waters. For that matter, many of the most virulent poisons like ricin and botulinus toxin are natural. Water crammed with bacteria and faecal matter is natural. Clean, safe drinking water from a tap is artificial. Yet we can’t help reacting like puppets when the advertisers use those magic words.