Smart hydrogels based on natural polymers present an opportunity to fabricate responsive scaffolds that provide an immediate and reversible reaction to a given stimulus. Modulation of mechanical characteristics is especially interesting in myocyte cultivation, and can be achieved by magnetically controlled stiffening. Here, hyaluronan hydrogels with carbonyl iron particles as a magnetic filler are prepared in a low-toxicity process. Desired mechanical behaviour is achieved using a combination of two cross-linking routes-dynamic Schiff base linkages and ionic cross-linking. We found that gelation time is greatly affected by polymer chain conformation. This factor can surpass the influence of the number of reactive sites, shortening gelation from 5 h to 20 min. Ionic cross-linking efficiency increased with the number of carboxyl groups and led to the storage modulus reaching 103 Pa compared to 101 Pa-102 Pa for gels cross-linked with only Schiff bases. Furthermore, the ability of magnetic particles to induce significant stiffening of the hydrogel through the magnetorheological effect is confirmed, as a 103-times higher storage modulus is achieved in an external magnetic field of 842 kA·m-1. Finally, cytotoxicity testing confirms the ability to produce hydrogels that provide over 75% relative cell viability. Therefore, dual cross-linked hyaluronan-based magneto-responsive hydrogels present a potential material for on-demand mechanically tunable scaffolds usable in myocyte cultivation.

• Klíčová slova
• Schiff base, hyaluronan, hydrodynamic radius, magnetorheology, smart hydrogels, tissue engineering,
• MeSH
• hydrogely * chemie   MeSH
• kyselina hyaluronová * MeSH
• polymery MeSH
• polysacharidy MeSH
• reologie MeSH
• Publikační typ
• časopisecké články MeSH
• Názvy látek
• hydrogely * MeSH
• kyselina hyaluronová * MeSH
• polymery MeSH
• polysacharidy MeSH

A new hyaluronan derivative modified with β-cyclodextrin units (CD-HA) was prepared via the click reaction between propargylated hyaluronan and monoazido-cyclodextrin (CD) to achieve a degree of substitution of 4%. The modified hyaluronan was characterized by 1H-nuclear magnetic resonance spectroscopy (NMR) and size exclusion chromatography. Subsequent 1H-NMR and isothermal calorimetric titration experiments revealed that the CD units on CD-HA can form virtual 1:1, 1:2, and 1:3 complexes with one-, two-, and three-site adamantane-based guests, respectively. These results imply that the CD-HA chains used the multitopic guests to form a supramolecular cross-linked network. The free CD-HA polymer was readily restored by the addition of a competing macrocycle, which entrapped the cross-linking guests. Thus, we demonstrated that the new CD-HA polymer is a promising component for the construction of chemical stimuli-responsive supramolecular architectures.

• Klíčová slova
• click reaction, cyclodextrin, host-guest systems, sodium hyaluronan, supramolecular network,
• MeSH
• beta-cyklodextriny chemická syntéza   chemie   MeSH
• click chemie MeSH
• kalorimetrie MeSH
• kyselina hyaluronová chemická syntéza   chemie   MeSH
• magnetická rezonanční spektroskopie MeSH
• molekulární struktura * MeSH
• polymery chemická syntéza   chemie   MeSH
• Publikační typ
• časopisecké články MeSH
• Názvy látek
• beta-cyklodextriny MeSH
• betadex MeSH Prohlížeč
• kyselina hyaluronová MeSH
• polymery MeSH