Cellulose-Based Hydrogels for Pharmaceutical and Biomedical Applications

Abstract

Hydrogels, the hydrophilic polymers, exhibit a three-dimensional network that can swell and retain the water molecules or any liquid in its structure, ten to 1000 times higher than its normal weight. The chemical cross-linking, physical entanglement, hydrogen bonds, and the ionic bonds are responsible to achieve the network of hydrogels. Hydrogels based on natural polymers like chitosan and cellulose are of great interest because of their abundant availability and biocompatibility and biodegradability. Natural polymer-based hydrogels have been used extensively in biomedicine, bioengineering, agriculture, and horticulture such as drug delivery, food, cosmetics, high water-absorbing resin, contact lenses, corneal implant, and substitutes for the skin, tendons, ligaments, cartilage, and bone due to their excellent hydrophilicity, permeability, compatibility, and low friction coefficient. Hydrogels specially cellulose ethers possess a remarkable combination of important properties for pharmaceutical and biomedical applications, e.g., as carriers for drug targeting, sustained release of drugs, vaccine bullets, and materials for the disintegration of matrix tablets. For the treatment of severe skin burns and in the regeneration of cardiac, vascular, neural, and cartilage bone tissues, these cellulose derivatives are very useful. In this regard bioactive hydrogels can be properly designed to induce at least partial skin regeneration. Cellulose-based hydrogels cross-linked with hyaluronic acid induce a good proliferation of keratinocytes, as a result of a scratch wound model in in vitro culture. Literature data have proposed the use of CMC- and HEC-based hydrogels as water absorbents in treating edemas. Hydrogels are also used as water absorbents for various applications in personal hygiene products or as biomedical devices, like soft contact lenses, lubricating surface coatings, phantoms for ultrasound-based imaging, etc.