ABSTRACT

Various pharmaceutical nanocarriers, such as nanospheres, nanocapsules, liposomes, micelles, polymeric nanoparticles, dendrimers, nanotubes, cell ghosts, lipoproteins, and some others, are widely used for experimental (and even clinical) delivery of therapeutic and diagnostic agents (Gregoriadis 1988, Müller 1991, Rolland 1993, Torchilin 2006a,b, 2008). e surface modi- cation of these carriers is o en used to control their properties in a desirable fashion and make them simultaneously perform several di erent functions. e most important results of such modi cation(s) include

Increased longevity and stability in circulation• Changed biodistribution• Targeting e ect• Stimuli(pH or temperature)-sensitivity• Contrast properties•

Frequent surface modi ers (used separately or simulatenously) include

Soluble synthetic polymers (to achieve carrier longevity)• Speci c ligands, such as antibodies, peptides, folate, trans-• ferrin, sugar moieties (to achieve the targeting e ect) pH-or temperature-sensitive copolymers (to impart • stimuli-sensitivity) Chelating compounds, such as EDTA, DTPA, or deferox-• amine (to add a diagnostic/contrast moiety onto a drug carrier)

Evidently, di erent modi ers can be combined on the surface of the same nanoparticular drug carrier providing it with a

combination of useful properties (e.g., longevity and targetability, targetability and stimuli-sensitivity, or targetability and contrast properties).