title: Targeted silencing of Survivin in cancer cells by siRNA loaded chitosan magnetic nanoparticles.
abstract: The aim of this study was to silence Survivin expression, related with drug-resistance, via siRNA-loaded CS-MNPs.
  
  
  
  The highest siRNA-loading efficiency was achieved at siRNA:CS-MNP ratio of 1:2. Nanoparticles had spherical morphology and homogenous size distribution in TEM. After siRNA loading, core sizes (3-5 nm) of CS-MNPs didn't change significantly, however hydrodynamic diameters increased ~10 nm, indicating swelling of chitosan coat due to efficient siRNA loading. 73% of siRNA was pH-dependently released at 24hours, after 30% burst release at first 3.5hours. Stability was high enough to keep siRNAs in CS-MNPs at pH7.2. Cellular-internalization of Survivin-siRNA-CS-MNPs was high and localized in cytoplasm of cells.
  
  
  
  Although, mock-siRNA loaded/unloaded CS-MNPs weren't cytotoxic, cell-death of breast cancer cells was significantly increased, after the treatment of Survivin-siRNA-loaded CS-MNPs. This reveals, successful loading of Survivin-siRNA on CS-MNPs and significant silencing of Survivin expression by triggering cell-death. Consequently, CS-MNPs are highly efficient delivery systems for intact siRNAs.
authors.affiliation: a Department of Biotechnology , Middle East Technical University , Ankara , Turkey.
authors.forename: Gozde
authors.initials: G
authors.lastname: Unsoy
authors.affiliation: a Department of Biotechnology , Middle East Technical University , Ankara , Turkey.|b Department of Biological Sciences , Middle East Technical University , Ankara , Turkey.
authors.forename: Ufuk
authors.initials: U
authors.lastname: Gunduz
mesh_terms: D001943:Breast Neoplasms / Q000235:genetics* / Q000473:pathology; D016923:Cell Death / Q000235:genetics; D048271:Chitosan / Q000737:chemistry; D003593:Cytoplasm / Q000378:metabolism; D019008:Drug Resistance, Neoplasm; D005260:Female; D020868:Gene Silencing; D006801:Humans; D006863:Hydrogen-Ion Concentration; D051034:Inhibitor of Apoptosis Proteins / Q000235:genetics*; D061986:MCF-7 Cells; D058185:Magnetite Nanoparticles; D010316:Particle Size; D034741:RNA, Small Interfering / Q000008:administration & dosage*; D000077022:Survivin; D013997:Time Factors
chemical_list: C107489:BIRC5 protein, human; D051034:Inhibitor of Apoptosis Proteins; D058185:Magnetite Nanoparticles; D034741:RNA, Small Interfering; D000077022:Survivin; D048271:Chitosan
keywords: Chitosan; doxorubicin resistant MCF-7 cells; magnetic nanoparticles; survivin siRNA; targeted drug delivery