Tumor Targeting of Polymeric Nanoparticles Conjugated with Peptides, Saccharides, and Small Molecules for Anticancer Drugs

Targeting drugs or pharmaceutical compounds to tumor site increases cancer treatment efficiency and therapeutic outcome. Nanoparticles are unique delivery systems for site-targeting within an organism. Many novel technologies have been established in drug research and development area. Nanotechnology now offers nanometer size polymeric nanoparticles and these particles direct drugs to their targets, protect drugs against degradation, and release the drug in a controlled manner. Modification of nanoparticle surface by molecules leads to prolonged retention and accumulation in the target area of the organism. Current efforts of designing polymeric nanoparticles include drug activation in the target area, controlled drug release at the site upon stimulation, and increased drug loading capacity of drug polymer conjugates. Recent progress in molecular mechanism elucidation of cancer cell and rising research in nanoparticle designs may provide efficient cancer treatment modality and innovative nanoparticle designs in the near future. Recent years have seen many developments in the field of innovative peptide based drug nanoparticles. Although none of them approved to be used in clinics yet, peptides are promising structures due to their simple and nonantigenic nature. Biodegradable materials are also preferred materials in drug delivery. Polysaccharide-based micelle systems improve hydrophobic drug and protein delivery. Ease of saccharide structure modification improves pharmacokinetic and pharmacodynamic properties of drug molecules as well as their delivery to a specific site in a controlled manner and sustained rate. Small molecules, especially drugs, conjugated to nanoparticles and several nanoparticles of this type are in the clinical trials and at the market. This review provides recent developments of polymeric nanoparticles conjugated with peptides, saccharides, and small molecules in cancer theraphy.