Influence of charge on FITC-BSA-loaded chondroitin sulfate-chitosan nanoparticles upon cell uptake in human Caco-2 cell monolayers

Int J Nanomedicine. 2012;7:4861-72. doi: 10.2147/IJN.S34770. Epub 2012 Aug 10.


Background and methods: Chondroitin sulfate-chitosan (ChS-CS) nanoparticles and positively and negatively charged fluorescein isothiocyanate-conjugated bovine serum albumin (FITC-BSA)-loaded ChS-CS nanoparticles were prepared and characterized. The properties of ChS-CS nanoparticles, including cellular uptake, cytotoxicity, and transepithelial transport, as well as findings on field emission-scanning electron microscopy, transmission electron microscopy, and confocal laser scanning microscopy were evaluated in human epithelial colorectal adenocarcinoma (Caco-2) fibroblasts. ChS-CS nanoparticles with a mean particle size of 250 nm and zeta potentials ranging from -30 to +18 mV were prepared using an ionic gelation method.

Results: Standard cell viability assays demonstrated that cells incubated with ChS-CS and FITC-BSA-loaded ChS-CS nanoparticles remained more than 95% viable at particle concentrations up to 0.1 mg/mL. Endocytosis of nanoparticles was confirmed by confocal laser scanning microscopy and measured by flow cytometry. Ex vivo transepithelial transport studies using Caco-2 cells indicated that the nanoparticles were effectively transported into Caco-2 cells via endocytosis. The uptake of positively charged FITC-BSA-loaded ChS-CS nanoparticles across the epithelial membrane was more efficient than that of the negatively charged nanoparticles.

Conclusion: The ChS-CS nanoparticles fabricated in this study were effectively endocytosed by Caco-2 fibroblasts without significant cytotoxicity at high nanoparticle concentrations. ChS-CS nanoparticles represent a potential novel delivery system for the transport of hydrophilic macromolecules.

Keywords: cell uptake; chitosan; chondroitin sulfate; cytotoxicity; nanoparticles.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Adsorption
  • Caco-2 Cells
  • Cell Membrane / chemistry*
  • Cell Membrane / metabolism*
  • Chitosan / chemistry*
  • Chondroitin Sulfates / chemistry*
  • Fluorescein-5-isothiocyanate / chemistry*
  • Humans
  • Nanocapsules / chemistry*
  • Serum Albumin, Bovine / pharmacokinetics*
  • Static Electricity
  • Surface Properties


  • Nanocapsules
  • Serum Albumin, Bovine
  • Chondroitin Sulfates
  • Chitosan
  • Fluorescein-5-isothiocyanate