Alginate
| Autor: | Constantinos Tsitsilianis, Zacharoula Iatridi, Sofia-Falia Saravanou, Konstantinos Safakas |
|---|---|
| Rok vydání: | 2021 |
| Předmět: |
Materials science
Magnetic Resonance Spectroscopy Chemical Phenomena Orders of magnitude (temperature) Alginates sol–gel transition 02 engineering and technology Chemistry Techniques Synthetic 010402 general chemistry 01 natural sciences Lower critical solution temperature Catalysis Article Inorganic Chemistry thermo-responsive lcsh:Chemistry shear-responsive Biopolymers Rheology Side chain Copolymer alginate Physical and Theoretical Chemistry Molecular Biology lcsh:QH301-705.5 Spectroscopy LCST adjustment Acrylamides Organic Chemistry Temperature Hydrogels General Medicine Dynamic mechanical analysis 021001 nanoscience & nanotechnology Grafting 0104 chemical sciences Computer Science Applications rheological properties PNIPAM-based graft copolymers Chemical engineering lcsh:Biology (General) lcsh:QD1-999 Self-healing hydrogels hydrogel 0210 nano-technology injectability |
| Zdroj: | International Journal of Molecular Sciences, Vol 22, Iss 3824, p 3824 (2021) International Journal of Molecular Sciences Volume 22 Issue 8 |
| ISSN: | 1422-0067 |
| Popis: | Graft copolymers of alginate backbone and N-isopropylacrylamide/N-tert-butylacrylamide random copolymer, P(NIPAMx-co-NtBAMy), side chains (stickers) with various NtBAM content were designed and explored in aqueous media. Self-assembling thermoresponsive hydrogels are formed upon heating, in all cases, through the hydrophobic association of the P(NIPAMx-co-NtBAMy) sticky pendant chains. The rheological properties of the formulations depend remarkably on the NtBAM hydrophobic content, which regulates the lower critical solution temperature (LCST) and, in turn, the stickers’ thermo-responsiveness. The gelation point, Tgel, was shifted to lower temperatures from 38 to 20 °C by enriching the PNIPAM chains with 20 mol % NtBAM, shifting accordingly to the gelation temperature window. The consequences of the Tgel shift to the hydrogels’ rheological properties are significant at room and body temperature. For instance, at 37 °C, the storage modulus increases about two orders of magnitude and the terminal relaxation time increase about 10 orders of magnitude by enriching the stickers with 20 mol % hydrophobic moieties. Two main thermo-induced behaviors were revealed, characterized by a sol–gel and a weak gel–stiff gel transition for the copolymer with stickers of low (0.6 mol %) and high (14, 20 mol %) NtBAM content, respectively. The first type of hydrogels is easily injectable, while for the second one, the injectability is provided by shear-thinning effects. The influence of the type of media (phosphate buffer (PB), phosphate-buffered saline (PBS), Dulbecco’s modified Eagle’s medium (DMEM)) on the hydrogel properties was also explored and discussed. The 4 wt % NaALG-g-P(NIPAM80-co-NtBAM20)/DMEM formulation showed excellent shear-induced injectability at room temperature and instantaneous thermo-induced gel stiffening at body temperature, rendering it a good candidate for cell transplantation potential applications. |
| Databáze: | OpenAIRE |
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