Semi-IPN- and IPN-Based Hydrogels

Abstract

Semi-interpenetrating polymer networks (semi-IPNs) and interpenetrating polymeric networks (IPNs) have emerged as innovative materials for biomedical and pharmaceutical applications. The interest in these structures is due to the possibility of combining the favorable properties of each polymeric component of the IPNs or semi-IPNs leading to a new system with properties that often differ from those of the two single components. In this respect, polysaccharides represent an opportunity in this field, combining a general biocompatibility and a good availability. Moreover, the functional groups along the polymer chains allow chemical derivatization, widening the possibilities in semi-IPNs and IPNs building up. At the same time, materials based on proteins are often used in this field, due to their similarity to the materials present in the human body. All these overall properties allow tailoring new materials, thus designing desired properties and preparing new hydrogels useful in the biomedical field. In the present chapter, we chose to describe systems prepared starting from the most important and studied hydrogel-forming polysaccharides: alginate, hyaluronic acid, chitosan, dextran, gellan, and scleroglucan. Besides, systems based on proteins, such as gelatin, collagen, and elastin, are also described. With this chapter, we aim describing the routes already traveled in this field, depicting the state of the art and hoping to raise interest in designing new promising strategies useful in biomedical and pharmaceutical applications.

Chitosan-based hydrogel for treatment of temporomandibular joint arthritis

“…Due to their hydrophilic characteristic, GG hydrogels provide an ideal environment with the necessary hydration for recovery from injuries, not allowing cytotoxic reactions to the body [27] . The result of this work reveals that the mass of the hydrogels is formed, in large part, by H 2 O, linked to the gellan gum through the junction zones previously mentioned, revealing an extremely important characteristic for this application [8] . The loss of mass at a temperature of 90°C makes the sterilization process with humid heat unfeasible, carried out in an autoclave at 121°C.…”

“…This helical geometry is promoted by the connection in the gelano repeating unit. It is well known that gellan gum can form hydrogels, which consist of a threedimensional polymeric network that retains large amounts of water and are promising biomaterials in the treatment of joint degenerations [7,8] .…”

Large-Scale Spinning Approach to Engineering Knittable Hydrogel Fiber for Soft Robots

“…During the polymerization of AAm by UV irradiation, the PAAm networks gradually formed around PAMPS. Subsequently, part of the PAMPS chains were expelled to the surface and out of the network , with water molecules to generate the lubrication layer. Besides, the water content in the pregel solution would also affect the liquid layer.…”

“…Moreover, balancing the mechanical strength and stimuli-responsive performance is yet another challenge. Most hydrogel fibers with fast actuation performance are vulnerable to breakdown even upon low applied strain states, far from the requirement of manufacturing into desired stimuli-responsive structures, ,− limiting the further practical application of fiber actuators in complicated and wearable soft robotic systems.…”

Study of Several Alginate-Based Hydrogels for In Vitro 3D Cell Cultures

“…By studying the growth states of cells on the 2D plates and in the 3D hydrogels, it is found that those cells grown on the 2D plates contact each other easily after several days of culture and inhibit the further increase in cell density [ 44 , 45 , 46 , 47 , 48 ]. However, in the 3D hydrogels, the contact inhibition phenomena can be effectively alleviated.…”