Fig. 2
Active drug delivery using targeted ligand/moieties and stimuli-responsive nanoformulations. Figure presents the model of diblock co-polymer nanoparticles with protective cover around the core and stimuli-response shell. Passively circulated nanoparticles accumulate in tumors via enhanced permeability and retention (EPR) effect and are released into extracellular environment of tumor. The attachment of homing ligands, targeted against specific moieties on the surface of cancer cells makes available for recognition of tumor cells from normal cells. Additionally, the specificity of nanoparticles-based therapeutics might be enhanced due to employment of nanosystems sensitive to triggering by external factors, such as temperature, light, and magnetic field, alternations in pH value or as effect of biological activity of enzymes, which allows for release of factors-activated payload drugs into cancer cells via receptor-mediated endocytosis, phagocytosis, pinocytosis or macropinocytosis