Facile strategy to construct a self-healing and biocompatible cellulose nanocomposite hydrogel via reversible acylhydrazone

Hydrogel Properties and Their Impact on Regenerative Medicine and Tissue Engineering

“…The classification of self-healing mechanisms is summarized in Table 2 and is presented in Figure 3. [66,67] Acylhydrazone bonds [68,69] Microcapsule [70,71] Host-guest interactions [72][73][74] Boronate-diol complexation [75,76] Hydrogen bond [77][78][79] Diels-Alder click chemistry [80][81][82] Hydrophobic interactions [83,84] Disulfide bonds [85,86] π-π stacking [87,88] Imine bonds (Schiff base) [89,90] Electrostatic (or ionic) interaction is based on the interaction between ions incorporated into the HG matrix ( Figure 3A). By the mutual attraction of oppositely charged ions or ions and polymer chains, the HG structure can be reconstructed, e.g., between two pieces of HG placed on each other [66].…”

“…These bonds are mainly developed between aldehyde or ketone groups and imine groups derived from acylhydrazine. An example of an HG in which these associations were used is the structure developed by Xiao et al [68]. The HG exhibited a significant possibility of self-healing, which is explained by the ability of acylhydrazone bonds to recreate these bonds reversibly.…”

Insight Into the Current Directions in Functionalized Nanocomposite Hydrogels

“…NC hydrogels showed significant improvement in tensile properties and self-recovery ability compared to the pure poly(acrylic acid) hydrogel. In a new effort to develop self-healing cellulose NC hydrogels, Xiao et al (2019) exploited acylhydrazineterminated polyethylene glycol to crosslink dialdehyde cellulose nanocrystals. Apart from an increase in the tensile and compressive strength of the hydrogel, self-healing efficiency, and biocompatibility of the hydrogel improved by 90 and 100%, respectively.…”

Stimuli-responsive hydrogel consisting of hydrazide-functionalized poly(oligo(ethylene glycol)methacrylate) and dialdehyde cellulose nanocrystals

“…Self-healing or the ability of self-repair is one of the properties that can be produced in a hydrogel with a rational crosslinking strategy. Two major crosslinking approaches can be employed to prepare self-healing hydrogel, namely dynamic noncovalent interactions (host-guest interactions, 12 metal ion co-ordinations, 13,14 electrostatic interactions 15,16 ) and reversible covalent bonds (boroneoxygen bonds, 17 sulfur-sulfur bonds (disulfide), 18 carbonnitrogen bonds (imine, 19 enamine, 20 and acylhydrazone [21][22][23] ), cyclohexenes (reversible Diels-Alder cycloaddition 24 )). Some of the reversible covalent bonds, such as acylhydrazone and disulfide are degradable in physiological environment, making them particularly advantageous in biomedical applications.…”

“…51 The pH of surrounding medium has a large influence on the thermo-mechanical properties and self-healing behavior of the hydrogels prepared with acylhydrazone bonds. 21 In this study, we prepared an in situ gelling hydrogel via acylhydrazone bonds using a mixture of hydrazide-functionalized POEGMA (POEGMA-H) and dialdehyde-functionalized CNC (DACNC). The rheological properties of the hydrogel can be tuned by changing the concentration of DACNC.…”