Examples of drug delivery systems using this route include that of PACA nanoparticles coated with transferrin, which were used for delivery of paclitaxel to S-180 tumor-bearing mice [29], or that of similarly targeted albumin nanoparticles loaded with azidothymidine, an antiretroviral agent, which was delivered to the brain in rat models of human immunodeficiency virus (HIV)/acquired immune deficiency syndrome (AIDS) [35]. Here, ALB is linked to AIDS.