Ence of macrophages, and in the main filtering organ, kidney, was observed. PEGylated cationic nanocarriers, loaded with negatively charged drugs, demonstrated longer blood circulation and better chances to penetrate the BBB (Kabanov and Batrakova 2004). Cationic nanogels built from PEGylated cationic polyethylenimine (PEI) networks have emerged as a promising drug delivery system to the CNS (Vino