High strain-rate response of injectable PAA hydrogel

Abstract

Hydrogel materials have been widely considered as potential soft tissue replacements because of their high permeability, hydrophilicity, and biocompatibility, as well as their low coefficient of friction. Injectable (thermo-responsive) hydrogels can provide support and cushioning at irregularly shaped disease sites, and are thus suitable for use in treating osteoarthritis or degenerative disc disease. However, while some injectable hydrogels have been proven to sustain human body weight during daily activities, their mechanical properties under harsh dynamic conditions have not been well documented. A specified injectable polyacrylic acid (PAA) hydrogel was prepared for this study. To simulate sudden impacts or unexpected shocks to the PAA hydrogel, the split Hopkinson pressure bar technique was utilized. The dynamic responses of various hydrogels at confined high strain rates (100-2590 s(-1)) were presented. Hydrogel specimens with 3.37, 6.75, and 13.5% acrylic acid (AAc) concentrations were tested in the following three different material conditions: raw, phosphate-buffered saline (PBS) swollen, and PBS swollen with elevated temperature (37 °C). The dynamic bulk moduli of the hydrogels varied from 1.55 to 47.8 MPa depending on the given hydrogel's AAc concentration and swollen condition.

Impact of the Type of Crosslinking Agents on the Properties of Modified Sodium Alginate/Poly(vinyl Alcohol) Hydrogels

“…In our research, we used alginates, which constitute linear polymers composed of (1→4)-α-L-guluronic acid blocks (GG), (1→4)-β-D-mannuronic acid blocks (MM) and, additionally, heteropolymeric sequences of M and G (MG blocks) [11,12]. Moreover, in the case of the preparation of hydrogel or composite materials, alginates are used together with some additional polymers, such as: poly acrylamide (PAAm) [13], poly(acrylic acid) (PAA) [14], gelatin [15], and chitosan [16], as well as PVA [17]. Poly(vinyl alcohol) is very important and interesting, because it characterized by biocompatibility, biodegradability and non-toxicity due to it is commonly used in the medical and pharmaceutical, such as: artificial organs, drug delivery as well as wound dressings.…”

Synthesis and Characterization of an Injectable and Hydrophilous Expandable Bone Cement Based on Poly(methyl methacrylate)

“…In addition, PAA has been widely used in tissue engineering owing to its small antigenic reaction in vivo. 30,31 Nevertheless, the studies focus primarily on the mechanical properties of bone cement since the inadequate mechanical properties of PAA should not be ignored. These are caused by the increased hydrophilicity as compared to neutral materials and the plasticizing of the solid-phase results by the interstitial fluid in vivo.…”

“…As a superabsorbent polyelectrolyte, poly­(acrylic acid) (PAA) is comprised of abundant intramolecular hydrophilic groups. In addition, PAA has been widely used in tissue engineering owing to its small antigenic reaction in vivo. , Nevertheless, the studies focus primarily on the mechanical properties of bone cement since the inadequate mechanical properties of PAA should not be ignored. These are caused by the increased hydrophilicity as compared to neutral materials and the plasticizing of the solid-phase results by the interstitial fluid in vivo. , With respect to the clinical application, changing the expansion performance of the bone cement necessitates intense focus.…”

Thermo-responsive hydrogels withN-isopropylacrylamide/acrylamide interpenetrating networks for controlled drug release

“…The result showed that, both LL and NPA were released quickly at first, after the burst period, the release rate slowed down and gradually reached the equilibrium. [29][30][31] Moreover, about 20 % of the LL and NPA were released within the first 2.5 h, and 80 % drugs were released at around 20 h, which were all behaved fast release performance. This indicated that LL and NPA not only were entrapped on the surface, but also distributed in the inner tunnels of the hydrogels.…”