Researchers are trying to shed light on open issues such as these. In spite of intensive efforts that serve to develop treatments for e.g. brain tumors which cannot be treated otherwise, it seems to be rather difficult so far to intentionally force sufficient quantities of nanoparticles over the blood-brain barrier. In view of this fact, it is rather improbable that nanoparticles other than the specially tailored ones will pass the barrier unintentionally.
For all that, it was found that nanoparticles can reach the brain by passing through the olfactory nerve. All experimental results obtained so far, however, indicate that the quantity of nanoparticles reaching the brain either via the blood-brain barrier or via the olfactory nerve in the olfactory epithelium of the nose is very small. Further research remains to be done to solve these issues.
- More information on nanoparticles and the brain can be found in the cross-cutting section at “nanoparticles at the blood-brain barrier” !!