Hybrid Hydrogel Networks by Photocrosslinking of Thermoresponsive alpha,omega-Itaconyl-PLGA-PEG-PLGA Micelles in Water: Influence of the Lithium Phenyl-2,4,6-Trimethylbenzoylphosphinate Photoinitinator

Modification of thermogelling biodegradable copolymers with functional groups enables further covalent crosslinking of physical micelle-based hydrogels formed at specific temperature in water. The resulting hybrid hydrogel network exhibits an increase in stiffness and degradation stability. In this work, synthesized well-defined thermoresponsive alpha,omega-itaconyl-poly(d,l-lactide-co-glycolide)-b-poly(ethylene glycol)-b-poly(d,l-lactide-co-glycolide) (alpha,omega-itaconyl-PLGA-PEG-PLGA) macromonomers with a high degree of itaconyl-substitution providing free double bonds are photocrosslinked in water at both 25 and 37 degrees C using lithium phenyl-2,4,6-trimethylbenzoylphosphinate (LiTPO) acting as water-soluble non-toxic photoinitiator. The effect of LiTPO on the thixotropic behavior of macromonomer in water at 25 degrees C without irradiation is evaluated. With the addition of a low amount of the photoinitiator (0.1 wt%), the degree of copolymer thixotropy increases. However, further increase in the photoinitiator concentration (0.5-3 wt%) leads to a lower degree of thixotropy. The photoinitiator is presumably interfering with the micellar self-assembly of the copolymer. This trend is also reflected in photocrosslinking efficiency, where the hybrid hydrogel networks with the highest storage moduli are achieved with very low concentrations of the photoinitiator (0.1 wt%) at 25 degrees C, while this trend is reversed at 37 degrees C. The hydrolytic stability of hydrogels prepared at 37 degrees C from 17 wt% macromonomer solution with 1% LiTPO exceeds 22 days.
Modifikace termosenzitivních biodegradabilních kopolymerů s funkčními skupinami umožňuje další kovalentní zesíťování fyzikálních hydrogelů na bázi micel vytvořených ve vodě při specifické teplotě. Výsledná hybridní hydrogelová síť vykazuje zvýšení tuhosti a degradační stability. V této práci byly syntetizováné dobře definované termoresponzivní , itaconylPLGAPEGPLGA) makromonomery s vysokým stupněm substituce kyseliny itakonové s volnými dvojnými vazbami, které byly fotosíťovány ve vodě při 25 i 37 ° C v přítonosti ve vodě rozpustného netoxického fotoiniciátoru lithium-fenyl 2,4,6-trimethylbenzoylfosfinátu (LiTPO).

Keywords

injectable hydrogels, photocrosslinking, photoinitiators, thermogellation, thixotropy, injektabilní hydrogel, fotosítování, fotoiniciátor, termogelace, tixotropie

Citation

Macromolecular Chemistry and Physics. 2020, vol. 221, issue 17, p. 1-9.
https://onlinelibrary.wiley.com/doi/epdf/10.1002/macp.202000165

Document type

Peer-reviewed

Document version

Published version

Language of document

en

Document licence

Creative Commons Attribution-NonCommercial 4.0 International
http://creativecommons.org/licenses/by-nc/4.0/