Bioresorbable and nonresorbable macroporous thermosensitive hydrogels prepared by cryopolymerization. Role of the cross-linking agent

Research output: Contribution to journalArticle

Abstract

Macroporous poly(N-isopropylacrylamide) (pNIPA) gels (so-called cryogels), cross-linked with different bisacryliccompounds, N,N'-methylenebisacrylamide (MBAAm) and dimethacrylate-tyrosine-lysine-tyrosine (DMTLT), were prepared through free-radical polymerization at subzero temperature in dioxane/water media. DMTLT is a hydrolytically degradable cross-linker with relatively hydrophobic character. The effects of different synthesis conditions, namely the concentration of monomers, the cross-linker, and the initiator in the reaction mixture, on the structure of the pNIPA-cryogels have been studied. The equilibrium swelling ratio of the DMTLT crosslinked pNIPA cryogels at temperatures below lower critical solution temperature (LCST) of pNIPA, was over ten times higher than that of the gels synthesized at room temperature from the same feed composition. The MBAAm cross-linked pNIPA cryogels synthesized in water exhibited the highest equilibrium swelling and the fastest response. The critical transition temperature, T-c, was lower (T-c approximate to 31 degrees C) for pNIPA-cryogels synthesized in dioxane/water media or cross-linked with DMTLT as compared to MBAAm cross-linked pNIPA cryogels synthesized in water (T-c approximate to 33 degrees C). Scanning electron microscopy (SEM) revealed different porous structure and pore surface morphology depending on the cross-linker (MBAAm or DMTLT) and the solvent (water or dioxane/water) used. Gels and cryogels were also characterized by SAXS, showing that the nanostructure of the samples is related to swelling.

Details

Authors
  • Paloma Perez
  • Fatima Plieva
  • Alberto Gallardo
  • Julio San Roman
  • Maria Rosa Aguilar
  • Isabelle Morfin
  • Frangoise Ehrburger-Dolle
  • Francoise Bley
  • Sergey Mikhalovsky
  • Igor Galaev
  • Bo Mattiasson
Organisations
Research areas and keywords

Subject classification (UKÄ) – MANDATORY

  • Industrial Biotechnology
Original languageEnglish
Pages (from-to)66-74
JournalBiomacromolecules
Volume9
Issue number1
Publication statusPublished - 2008
Publication categoryResearch
Peer-reviewedYes