Also another comment next to yours said 2-3cc.
The major component in atmospheric air, nitrogen (N2), is already abundant in the blood too, so it isn't an issue. If I remember correctly, our bodies are generally in equilibrium with the outside air in terms of N2 partial pressure.
Admittedly, a small air bubble in the blood bypasses a lot of the specialized membranes our alveoli use to make their gas exchange, but blood itself can manage a bit of air just fine.
If you're asking about the nanorobot, however: The article says it's not yet biodegradable to the degree they want to make it.
In addition, a bubble shows surface tension. This is exactly the problem of divers who surface too fast: the excess of air dissolved in the blood due to higher pressure aggregates into bubbles.
EDIT: By excess of air I mean Nitrogen. We don't have proteins to bind gaseous Nitrogen.
This only applies to veinous blood.
You do not want arterial blood to be messed with generally at all, as far as I understand.