Competitive ligand exchange of crosslinking ions for ionotropic hydrogel formation

Research output: Contribution to journalArticlepeer-review


  • Dave Bassett
  • Armend G. Håti
  • Thor B. Melø
  • Bjørn T. Stokke
  • Pawel Sikorski

Colleges, School and Institutes

External organisations

  • Norwegian University of Science and Technology


Currently there are limitations to gelation strategies to form ionically crosslinked hydrogels, derived in particular from a lack of control over the release kinetics of crosslinking ions, which severely restrict applications. To address this challenge, we describe a new approach to form hydrogels of ionotropic polymers using competitive displacement of chelated ions, thus making specific ions available to induce interactions between polymer chains and form a hydrogel. This strategy enables control of ion release kinetics within an aqueous polymer solution and thus control over gelation kinetics across a wide range of pH. The described technique simplifies or facilitates the use of ionotropic hydrogels in a range of applications, such as 3D printing, microfluidic-based cell encapsulation, injectable preparations and large scale bubble and solid free mouldable gels. We investigate a range of chelator-ion combinations and demonstrate this powerful method to form hydrogels across a wide range of pH and μm-cm length scales. We highlight our findings by applying this gelation strategy to some of the more challenging hydrogel application areas using alginate and polygalacturonate as model polymer systems.


Original languageEnglish
Pages (from-to)6175-6182
Number of pages8
JournalJournal of Materials Chemistry B
Issue number37
Publication statusPublished - 17 Aug 2016