Current Trends in Biomedical Hydrogels: From Traditional Crosslinking to Plasma-Assisted Synthesis

Abstract

The use of materials to restore or replace the functions of damaged body parts has been proven historically. Any material can be considered as a biomaterial as long as it performs its biological function and does not cause adverse effects to the host. With the increasing demands for biofunctionality, biomaterials nowadays may not only encompass inertness but also specialized utility towards the target biological application. A hydrogel is a biomaterial with a 3D network made of hydrophilic polymers. It is regarded as one of the earliest biomaterials developed for human use. The preparation of hydrogel is often attributed to the polymerization of monomers or crosslinking of hydrophilic polymers to achieve the desired ability to hold large amounts of aqueous solvents and biological fluids. The generation of hydrogels, however, is shifting towards developing hydrogels through the aid of enabling technologies. This review provides the evolution of hydrogels and the different approaches considered for hydrogel preparation. Further, this review presents the plasma process as an enabling technology for tailoring hydrogel properties. The mechanism of plasma-assisted treatment during hydrogel synthesis and the current use of the plasma-treated hydrogels are also discussed.

Methodology for characterizing the printability of hydrogels

“…In bioprinting processes, materials such as polylactic acid (PLA), light curing resins, or hydrogels can be used as printing matrix, although hydrogels are the most recommended. Hydrogels provide a matrix for tissues to regenerate while controlling the diffusion of molecules and cells [ 4 ] . The printability of hydrogels is an important factor in choosing the most suitable one in bioprinting studies.…”

Introductory Chapter: Hydrogels in Comprehensive Overviews, Recent Trends on Their Broad Applications

“…Initial research of hydrogels started in 1894 when the usage of inorganic salts led to a colloidal gel [1]. Once they come into contact with fluids, hydrogels proceed to incorporate and expand to create a three-dimensional (3D) structure considering the presence of hydrophilic groups (amino, hydroxyl, carboxyl, and amide) in their structure [2].…”

“…The current definition of hydrogel was established on the groundbreaking work of Lim and Wichterle, who used in 1960 gels based on poly (2-hydroxymethyl methacrylate) to create soft contact lenses. This novelty represented the onset of hydrogel investigation for applications in the biological field [1].…”

Recent Advances in Smart Hydrogels Prepared by Ionizing Radiation Technology for Biomedical Applications

“…Liu et al reviewed the progress of 3D printing hydrogel technology [ 23 ]. Taaca et al studied the preparation methods of hydrogels and emphasized the advantages of a plasma-based preparation of hydrogels [ 24 ]. This paper introduces the classification of hydrogels and other preparation methods.…”