Hydrogel and Effects of Crosslinking Agent on Cellulose-Based Hydrogels: A Review

Abstract

Hydrogels are hydrophilic polymer materials that can swell but are insoluble in water. Hydrogels can be synthesized with synthetic or natural polymers, but natural polymers are preferred because they are similar to natural tissues, which can absorb a high water content, are biocompatible, and are biodegradable. The three-dimensional structure of the hydrogel affects its water insolubility and ability to maintain its shape. Cellulose hydrogels are preferred over other polymers because they are highly biocompatible, easily accessible, and affordable. Carboxymethyl cellulose sodium (CMCNa) is an example of a water-soluble cellulose derivative that can be synthesized using natural materials. A crosslinking agent is used to strengthen the properties of the hydrogel. Chemical crosslinking agent is used more often than physical crosslinking agent. In this review, article, different types of crosslinking agents are discussed based on synthetic and natural crosslinking agents. Hydrogels that utilize synthetic crosslinking agent have advantages, such as adjustable mechanical properties and easy control of the chemical composition. However, hydrogels that use natural crosslinking agent have better biocompatibility and less latent toxic effect.

Design Considerations, Formulation Approaches, and Strategic Advances of Hydrogel Dressings for Chronic Wound Management

“…80 The physical cross-linkings between distinct polymers and polymeric chains have been proposed by a number of thermodynamical changes, including heating and/or cooling of the polymeric solution, lyophilization, lowering and/or increasing of pH, and appropriate choice of anionic and cationic polymers. 81 Designing of the physically cross-linked hydrogel includes the simple procedure of purification as there is no involvement of any kind of chemically toxic cross-linking agents. Thus, these hydrogels are a very good platform for wound healing due to their biocompatibility and nontoxicity.…”

Advances in the Physico-Chemical, Antimicrobial and Angiogenic Properties of Graphene-Oxide/Cellulose Nanocomposites for Wound Healing

“…Therefore, they represent a good alternative to water-insoluble cellulose. However, mechanical strength and toughness continue to be the most difficult problems, which scientists have attempted to solve in a variety of ways: (i) by the use of non-covalent (i.e., citric acid, polyphenols) or covalent (i.e., epichlorohydrin, aldehyde-based reagents, urea derivatives, carbodiimides and multifunctional carboxylic acids) crosslinking agents [ 41 ], (ii) by designing blends with other synthetic (i.e., polyurethane, poly (vinyl alcohol), polyvinylpyrrolidone) [ 42 ] or natural (i.e., collagen, gelatin, chitosan, k-carrageenan, alginate) biopolymers [ 43 ]; (iii) by employing gelling agents [ 44 ]; (iv) by using nanomaterials as fillers (i.e., graphene oxide derivatives, titanium oxide, silver nanoparticles, zinc oxide, ceramics) [ 45 , 46 , 47 ].…”

A Comprehensive Review of Food Hydrogels: Principles, Formation Mechanisms, Microstructure, and Its Applications

“…Every type of biomass resource imparts unique characteristics to CMC, such as exceptional absorption and adsorption, a high swelling ability, and superior optical properties. In addition to being advantageous for the production of CMC hydrogels, a high level of methylation groups in various types of biomass waste is also beneficial [81].…”