Research Advances in Mechanical Properties and Applications of Dual Network Hydrogels

Abstract

Hydrogels with a three-dimensional network structure are particularly outstanding in water absorption and water retention because water exists stably in the interior, making the gel appear elastic and solid. Although traditional hydrogels have good water absorption and high water content, they have poor mechanical properties and are not strong enough to be applied in some scenarios today. The proposal of double-network hydrogels has dramatically improved the toughness and mechanical strength of hydrogels that can adapt to different environments. Based on ensuring the properties of hydrogels, they themselves will not be damaged by excessive pressure and tension. This review introduces preparation methods for double-network hydrogels and ways to improve the mechanical properties of three typical gels. In addition to improving the mechanical properties, the biocompatibility and swelling properties of hydrogels enable them to be applied in the fields of biomedicine, intelligent sensors, and ion adsorption.

ECM-based bioadhesive hydrogel for sutureless repair of deep anterior corneal defects

“…Increases in the compressive modulus of the PEGDA-containing samples may be due to physical crosslinking of the crystalline domain of PEGDA 35 with the creation of a double network of GelMA and PEGDA hydrogels. 36 The improved mechanical properties of GelMA hydrogels by addition of PEGDA have been also reported by previous studies. 25,35,[37][38][39] Paper Biomaterials Science…”

“…This improved bioadhesive property of dCor/Gel-PEG in comparison to Gel-PEG hydrogel can be attributed to the formation of a double network following the rearrangement of triple precursor α-chains of digested collagen in dCor within the Gel-PEG hydrogels. 36 In addition, the presence of covalent bonds between -CH 2 in PEGDA and -NH 2 of lysine in digested proteins of dCor led to the formation of a Urethane Linkage, which is strongly responsible for the improved bioadhesiveness of this dual-network hydrogel to surrounding tissues. 41 Another key factor in designing corneal sealants is their transparency, as well as their ability to exchange nutrients, oxygen, and water within the sealant body.…”

Tailoring Network Topology in Mechanically Robust Hydrogels for 3D Printing and Injection

“…The absence of energy dissipation mechanisms often contributes to the excessive brittleness observed in conventional hydrogels. 26,27 Further, a heterogeneous network architecture arising from defects such as loops and dangling chains formed during the cross-linking process can lead to stress concentrations and catastrophic failure. 28−33 Despite an abundance of literature describing hydrogels as tissue scaffolds, the correlation between network connectivity and material performance is often overlooked in the tissue engineering field.…”

“…This involves primarily developing a nuanced understanding of their structure–property relationships. The absence of energy dissipation mechanisms often contributes to the excessive brittleness observed in conventional hydrogels. , Further, a heterogeneous network architecture arising from defects such as loops and dangling chains formed during the cross-linking process can lead to stress concentrations and catastrophic failure. − Despite an abundance of literature describing hydrogels as tissue scaffolds, the correlation between network connectivity and material performance is often overlooked in the tissue engineering field . A deeper understanding of the network structure can provide us with valuable insights for addressing the factors responsible for the hydrogels’ mechanical deficiencies.…”

Herbal molecule-mediated dual network hydrogels with adhesive and antibacterial properties for strain and pressure sensing

“…Recently, dual network (DN) hydrogels, first established in 2003 by Gong et al , 14 have been recently demonstrated to be effective in constructing flexible sensors possessing enhanced physicochemical properties and integrated multifunctionality. 15–18 For example, Li et al fabricated a tough DN hydrogel through combining thermoreversible κ-carrageenan hydrogel with polyacrylamide network, where the former rendered good recoverability and self-healing capability to the DN hydrogel while the latter enabled 3D printing by means of UV light-triggered photopolymerization. 19 Gu et al employed the host–guest interaction and dynamic covalent bond to prepare DN hydrogels, acquiring satisfactory comprehensive performance including stretchability, strength, remodeling ability, self-healing property, self-adhesiveness, and biocompatibility.…”