Antifreeze and Rheological Properties of Injectable Triblock Copolymer Hydrogels with Supramolecular Junctions

Abstract

ABC triblock copolymers composed of hydrophobic poly(𝝐-caprolactone) (PCL), zwitterionic poly(carboxybetaine methacrylate) midblock, and P(PEGMA-UPy 0.15 ) containing supramolecular ureidopyrimidinone moieties, poly(𝝐-caprolactone-block-carboxybetaine methacrylate-block-[poly(ethylene glycol) methyl ether methacrylate-co-(𝜶-methacryloyl-𝝎-(6-(3-(6-methyl-4-oxo-1,4-dihydropyrimidin-2-yl)ureido)hexylcarbamoyloxy)poly(ethylene glycol))]), are investigated to achieve multifunctional antifreeze hydrogels. The PCL and P(PEGMA-UPy 0.15 ) blocks induce the formation of physical network with a hierarchical nanostructure comprising hydrophobic PCL cores and supramolecular junctions, respectively. The super-hydrophilic nature of polyzwitterion midblocks and the confinement effect of the supramolecular junctions enhance the antifreeze performance, where the majority of water molecules remains supercooled below sub-zero temperature. The hydrogel relaxation characterized over a wide range of timescale reveals that the facile dynamics of the supramolecular junctions lead to the self-healing and injectability of the hydrogels. In conjunction with the biodegradable PCL cores, the antifreeze and rheological characteristics of the triblock copolymer hydrogels provide significant potential to use for cryo-preservable and bio-injectable drug storage and delivery.

Hazardous Gases-Responsive Photonic Crystals Cryogenic Sensors Based on Antifreezing and Water Retention Hydrogels

“…However, the traditional hydrogel sensor loses water in the air over time, and it is hard to use at low temperature. In order to improve the stability and practicability of the hydrogel, many researchers have focused on reducing the freezing point of the hydrogel by introducing salts, , organic solvents, − macromolecule, − ionic liquids, and others , to improve the water retention and antifreezing, , and organic solvents are widely added because of their suitability for hydrogels. There are generally two ways to incorporate organic solvents into hydrogels.…”