ABSTRACT
The endothelium is often regarded as a gatekeeper, playing an
important role in separating blood from the surrounding tissues and
regulating the passage of proteins and other molecules across the
blood vessels. This transport can either be transcellular or paracellu-
lar. The cytoskeletal structures of the endothelial cells play a pivotal
role in regulating this transport. This chapter attempts to discuss in
brief these two types of transport and the components and factors
governing them, an understanding ofwhich is essential for designing
more efficient drugs that can traverse the endothelium more
effectively for increased therapeutic benefits. Novel approaches for
enhancing the penetration of drugs are also reviewed here.
