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

Perez, Paloma, Plieva , Fatima, Gallardo, Alberto, San Roman, Julio, Aguilar, M.R., Morfin, Isabelle, Ehrburger-Dolle, Francoise, Bley, Francoise, Mikhalovsky, S.V., Yu Galaev, Igor and Mattiasson, Bo (2007) Bioresorbable and nonresorbable macroporus thermosensitive hydrogels prepared by cryopolymerization. Role of the cross-linking agent Biomacromolecules, 9 (1). pp. 66-74. ISSN 1525-7797

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Abstract

Macroporous poly(N-isopropylacrylamide) (pNIPA) gels (so-called cryogels), cross-linked with different bis-acrylic compounds, 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 cross-linked 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, Tc, was lower (Tc ≈ 31 °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 (Tc ≈ 33 °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.

Item Type:Journal article
Subjects:J000 Technologies > J400 Polymers and Textiles
DOI (a stable link to the resource):10.1021/bm7007668
Faculties:Faculty of Science and Engineering
Faculty of Science and Engineering > School of Pharmacy and Biomolecular Sciences
ID Code:7860
Deposited By:editor spbs
Deposited On:10 Nov 2010 15:05
Last Modified:21 Mar 2013 02:17

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