Colloid and Polymer Science

, Volume 290, Issue 10, pp 919–929 | Cite as

Effects of ionic strength on the size and compactness of chitosan nanoparticles

  • Helene JonassenEmail author
  • Anna-Lena Kjøniksen
  • Marianne Hiorth
Original Contribution


In this work, chitosan nanoparticles were prepared by ionotropic gelation of chitosan with tripolyphosphate (TPP). The effects of the ionic strength of the solvent employed in the particle preparation on the average size and compactness of the particles were investigated. In addition, the effects of the chitosan concentration and the crosslinker to polymer ratio on the particle characteristics were studied. The chitosan–TPP nanoparticles were characterized by dynamic light scattering, zeta potential, and turbidity measurements. The compactness of the nanoparticles was estimated with a method based on the size of the nanoparticles and the turbidity of the nanoparticle suspension. All the investigated preparation parameters, i.e., the ionic strength of the solvent, the chitosan concentration, and the TPP to chitosan ratio, affected the particle characteristics. For instance, smaller and more compact particles were formed in saline solvents, compared to particles formed in pure water. Further, the addition of monovalent salt rendered it possible to prepare particles in the nanometer size range at a higher polymer concentration. Solvent salinity is thus an important parameter to address in the preparation of chitosan nanoparticles crosslinked with TPP.


Nanoparticles Chitosan Tripolyphosphate Ionic strength Particle size Particle compactness 


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Copyright information

© Springer-Verlag 2012

Authors and Affiliations

  • Helene Jonassen
    • 1
    Email author
  • Anna-Lena Kjøniksen
    • 1
  • Marianne Hiorth
    • 1
  1. 1.Department of Pharmacy, School of PharmacyUniversity of OsloOsloNorway

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