title: Suppressing unspecific cell uptake for targeted delivery using hydroxyethyl starch nanocapsules.
abstract: Synthesizing nanocarriers with stealth properties and delivering a "payload" to the particular organ remains a big challenge but is the prime prerequisite for any in vivo application. As a nontoxic alternative to the modification by poly(ethylene glycol) PEG, we describe the synthesis of cross-linked hydroxyethyl starch (HES, M(w) 200,000 g/mol) nanocapsules with a size range of 170-300 nm, which do not show nonspecific uptake into cells. The specific uptake was shown by coupling a folic acid conjugate as a model targeting agent onto the surface of the nanocapsules, because folic acid has a high affinity to a variety of human carcinoma cell lines which overexpress the folate receptor on the cell surface. The covalent binding of the folic acid conjugate onto HES capsules was confirmed by FTIR and NMR spectroscopy. The coupling efficiency was determined using fluorescence spectroscopy. The specific cellular uptake of the HES nanocapsules after folic acid coupling into the folate-receptor presenting cells was studied by confocal laser scanning microscopy (CLSM) and flow cytometry.
authors: Max Planck Institute for Polymer Research, Ackermannweg 10, 55128 Mainz, Germany.
authors: Grit
authors: G
authors: Baier
authors: Daniela
authors: D
authors: Baumann
authors: Jörg Max
authors: JM
authors: Siebert
authors: Anna
authors: A
authors: Musyanovych
authors: Volker
authors: V
authors: Mailänder
authors: Katharina
authors: K
authors: Landfester
mesh_terms: D001692:Biological Transport; D045744:Cell Line, Tumor; D004337:Drug Carriers / Q000138:chemical synthesis* / Q000494:pharmacology; D004655:Emulsions; D005434:Flow Cytometry; D058973:Folate Receptors, GPI-Anchored / Q000378:metabolism; D005492:Folic Acid / Q000737:chemistry* / Q000378:metabolism; D006801:Humans; D006895:Hydroxyethyl Starch Derivatives / Q000737:chemistry*; D009682:Magnetic Resonance Spectroscopy; D018613:Microscopy, Confocal; D008856:Microscopy, Fluorescence; D053769:Nanocapsules / Q000737:chemistry* / Q000648:ultrastructure; D010316:Particle Size; D013010:Sonication; D017550:Spectroscopy, Fourier Transform Infrared
chemical_list: D004337:Drug Carriers; D004655:Emulsions; D058973:Folate Receptors, GPI-Anchored; D006895:Hydroxyethyl Starch Derivatives; D053769:Nanocapsules; D005492:Folic Acid