Molecular targeting of drug delivery systems to cancer.

This review presents molecular targeting approaches in anticancer drug delivery systems (DDS) and identifies new developments in these systems. Targeting approaches include passive targeting (enhanced permeability and retention effect), targeting specific tumor conditions, topical delivery and active targeting, namely, targeting organs, cells, intracellular organelles and molecules, sandwich targeting, promoter targeting, indirect targeting and targeting by external stimuli. A novel advanced proapoptotic anticancer DDS that utilizes several molecular targets will be considered. Experimental data suggest that this DDS can simultaneously: (1) induce cell death, (2) prevent adverse effects on healthy tissues; (3) suppress and prevent multidrug resistance; and (4) inhibit cellular antiapoptotic defense.