Hydrogels for Pharmaceutical and Biomedical Applications

Abstract

Hydrogels are crosslinked hydrophilic polymer structures that can imbibe large amounts of water or biological fluids. Hydrogels are one of the upcoming classes of polymer-based systems that embrace numerous biomedical and pharmaceutical applications. This review discusses various parameters of hydrogels such as surface properties, water content and swelling behavior, effect of nature of polymer, ionic content, and thermodynamics, all of which can influence the biomedical usage of hydrogels. Meanwhile, intelligent or environment-sensitive hydrogels and bioadhesive hydrogels continue to be important materials for medical applications; therefore, a part of this review is devoted to some of their important classes. Hydrogels are extensively used for various biomedical applications--tissue engineering, molecular imprinting, wound dressings materials, immunoisolation, drug delivery, etc. Thus, this review aims to throw light on the numerous applications that hydrogels have in the biomedical arena.

Polymeric Hydrogels: Characterization and Biomedical Applications

“…For the development of modern health care products, there has been an increased interest for polymers among the researchers, which can be attributed to the easy availability of the wide range of polymers with desirable properties. Some of the key applications include reconstruction of load bearing hip and knee joints, tendons replacement, development of matrix for tissue engineering and drug-delivery systems [2][3][4][5][6][7][8][9][10][11]. In this review article we will discuss some of the characterization methods and applications of a special class of polymers known as hydrogels.…”

“…The examples of physical hydrogels include poly(vinyl alcohol)/glycine hydrogels, gelatin gels and agar-agar gels. Hydrogels can also be categorized as conventional and stimuli responsive hydrogels [2]. Conventional hydrogels are cross-linked polymer chains which absorb water when put in an aqueous media and there is no change in the equilibrium swelling with the change in the pH, temperature or electric field of the surrounding environment while the stimuli responsive hydrogels are the polymeric networks which change their equilibrium swelling with the change of the surrounding environment.…”

“…Hence, determination of the amount of water imbibed within the hydrogel is an important criterion for characterizing the hydrogel for biomedical applications and is often represented in terms of % age swelling (% S) [2]. The % age swelling of the hydrogel is directly proportional to the amount of water imbibed within the hydrogel.…”

“…The slope of the line is used for calculation and is used to determine the diffusion coefficient from equation (2). The structure, pore size and polymer composition of gel are taken into account by the diffusion coefficient [12].…”

Synthesis and Characterization of N-[3-(Dimethylamino)propyl]methacrylamide / (nano SiO2, amine-modified nano SiO2, and expanded perlite) Nanocomposite Hydrogels

“…The second method involves crosslinking of linear polymers by irradiation, or by chemical compounds. [9][10][11][12] The monomers used in the preparation of the ionic polymer network contain an ionizable group, a group that can be ionized, or a group that can undergo a substitution reaction after the polymerization is completed. As a result, hydrogels synthesized contain weakly acidic groups like carboxylic acids, or a weakly basic group like substituted amines, or a strong acidic and basic group like sulfonic acids, and quaternary ammonium compounds.…”