title: Programmed drug delivery: nanosystems for tumor targeting.
abstract: Programmed nanoscaled systems are emerging that may be very useful for tumor-targeted drug delivery: novel nanoparticles are pre-programmed to alter their structure and properties during the drug delivery process to make them most effective for the different extra- and intracellular delivery steps. Programming is effected by the incorporation of molecular sensors that are able to respond to physical or biological stimuli, including changes in pH, redox potential or enzymes. Tumor-targeting principles include systemic passive targeting and active receptor targeting. Physical forces (e.g., electric or magnetic fields, ultrasound, hyperthermia or light) may contribute to focusing and triggered activation of nanosystems. Biological drugs delivered with programmed nanosystems also include plasmid DNA, small interfering RNA and related therapeutic nucleic acids formulated as 'synthetic viruses'.
authors.affiliation: Ludwig-Maximilians-Universität, Professor and Chairman of Pharmaceutical Biology-Biotechnology, Department of Pharmacy, Butenandtstrasse 5-13, D-81377, Munich, Germany. ernst.wagner@cup.uni-muenchen.de
authors.forename: Ernst
authors.initials: E
authors.lastname: Wagner
mesh_terms: D000818:Animals; D000970:Antineoplastic Agents / Q000008:administration & dosage* / Q000737:chemistry / Q000378:metabolism; D002626:Chemistry, Pharmaceutical; D004247:DNA / Q000378:metabolism; D003692:Delayed-Action Preparations; D004337:Drug Carriers; D016503:Drug Delivery Systems / Q000379:methods*; D018014:Gene Transfer Techniques; D006801:Humans; D036103:Nanotechnology; D009369:Neoplasms / Q000378:metabolism
chemical_list: D000970:Antineoplastic Agents; D003692:Delayed-Action Preparations; D004337:Drug Carriers; D004247:DNA