These indicate the relatively high impermeability of the BBB in PD compared to other brain diseases such as the ischemic stroke, although increased permeability of the BBB has been identified in patients with PD.[248] Interestingly, PAMAM dendrimers decorated with lactoferrin were able to deliver plasmid DNA (encoding human glial cell‐line derived neurotrophic factor) into following i.v. administration. This evidence concerns the gene LTF and Parkinson disease.