N,O6-partially acetylated chitosan nanoparticles hydrophobically-modified for controlled release of steroids and vitamin E

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  • Javier Perez Quinones, Center of Natural Products, Faculty of Chemistry, University of Havana, Cuba
  • Kurt Vesterager Gothelf
  • Jørgen Kjems
  • Angeles Maria Heras Caballero, Instituto de Estudios Biofuncionales/Dpto Química Física II, Facultad de Farmacia, Universidad Complutense de Madrid, Spain
  • Claudia Schmidt, Department of Chemistry, University of Paderborn, Germany
  • Carlos Peniche Covas, Center of Biomaterials, University of Havana, Cuba
Diosgenin, two synthetic analogs of brassinosteroids, testosterone and dl-α-tocopherol were covalently linked to synthetic water-soluble N,O6-partially acetylated chitosan, for their controlled release. Drug linking was confirmed by FTIR spectroscopy and proton NMR. Conjugates were also characterized by differential scanning calorimetry and wide-angle X-ray diffraction. These conjugates formed self-assembled nanoparticles in aqueous solution with particle sizes ranging from 197 to 358 nm and drug contents between 11.8 and 56.4% (w/w). Spherical 30–60 nm nanoparticles were observed by scanning electron microscopy and transmission electron microscopy upon drying. In vitro release studies performed at acid pH indicated a drug release dependence on substitution degree and particle sizes. Almost constant release rates were observed during the first 6–8 h. Brassinosteroids-modified nanoparticles showed good agrochemical activity in radish seeds bioassay at 10−1 to 10−4 mg mL−1. Tocopheryl-modified nanoparticles exhibited radical scavenging activity in DPPH test.
Original languageEnglish
JournalCarbohydrate Polymers
Volume91
Issue1
Pages (from-to)143-151
Number of pages9
ISSN0144-8617
DOIs
Publication statusPublished - 2 Jan 2013

    Research areas

  • Controlled release, Chitosan, Self-assembled nanoparticles, Steroids, Tocopherol

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