Skip to main content
. Author manuscript; available in PMC: 2014 Mar 29.
Published in final edited form as: Drug Deliv Transl Res. 2012 May 31;2(3):169–186. doi: 10.1007/s13346-012-0072-4

Figure 3. Functionalization and transport of drug delivery systems.

Figure 3

(a) A schematic representation of a model drug delivery system is shown. Drugs can be encapsulated, while the carrier shell can be functionalized to display poly(ethylene-glycol) (PEG) for stealth properties and prolonged circulation, as well as affinity moieties to target cells and tissues of therapeutic interest. (b) Drug carriers that are targeted to cell receptors involved in endocytosis can be internalized by cells. This often leads to transport into endo-lysosomal vesicles for: (i) pH dependent release of drugs aimed to act within this compartment or the cytosol (if permeable); (ii) endosomal poration by reactive materials, allowing leakage of drugs or biologicals into the cytoso; or (iii) transcytosis with release in the abluminal side of the cell.