Poly(acrylamide‐co‐acrylic acid)/chitosan semi‐interpenetrating hydrogel for pressure sensor and controlled drug release

Abstract

With high biocompatibility and pH‐sensitivity, hybrid hydrogels of chitosan (CS) have been widely used in sensor, drug release systems, adsorption, agriculture, and other fields. Herein, a poly(acrylamide‐co‐acrylic acid)/chitosan [P(AM‐co‐AA)/CS] hydrogel with semi‐interpenetrating (semi‐IPN) network was synthesized through in situ copolymerization of acrylamide (AM), N,N′‐methylene‐bisacrylamide (MBAA) and acrylic acid (AA) solution of chitosan using potassium persulfate (KPS) and sodium bisulfite (SBS) as oxidation‐reduction co‐initiators. CS‐AA complex monomer was prepared by dissolving CS in AA solution. Meanwhile, MBAA was used as a crosslinker to enhance the strength of the resulted hybrid hydrogels via introducing chemical crosslinking to the substrate P(AM‐co‐AA) copolymer. The morphology of the freeze‐dried sample of P(AM‐co‐AA)/CS hydrogel shows dense interconnected pores. When the CS content is 2.4%, the P(AM‐co‐AA)/CS hydrogel has a compressive stress of 5.06 MPa at strain of 90.0% and a tensile strength of 161.71 kPa at strain of 1082.0%. The CP(AM‐co‐AA)/CS hydrogel also demonstrates extraordinary antifatigue property under cyclic compression of 85%. Because of the outstanding mechanical properties, a capacitive pressure sensor using P(AM‐co‐AA)/CS hydrogel as a dielectric with good durability and linearity at low operating voltage was fabricated. Besides, the water uptake of the P(AM‐co‐AA)/CS hydrogels is pH‐sensitive, and the hydrogels could serve as a matrix for loading of ranitidine hydrochloride with controlled release under different pH environments.

Tubular chitosan hydrogels with a tuneable lamellar structure programmed by electrical signals

“…It is noted that the tensile strength of traditional chitosan hydrogel formed by base neutralization is in the range of 0.1-1.25 MPa. [21][22][23] We also found that prolonging the deposition time from 1 to 3 h increased the toughness of the hydrogel tubes. As shown in Fig.…”

Composite Polyvinylpyrrolidone–Sodium Alginate—Hydroxyapatite Hydrogel Films for Bone Repair and Wound Dressings Applications

“…However, the use of SA hydrogels is limited, since SA is relatively inert when interacting with integrins of mammalian cells [48]; therefore, it is not adhesive for cells. In order to improve these properties, an interpenetrating hydrogel design looks promising [49][50][51].…”

Double dynamic bonds tough hydrogel with high self‐healing properties based on acylhydrazone bonds and borate bonds

“…As Figure 1B, we chose the common monomer AAm, because its polymer was non‐toxic and commercially available, and the polymer PVA prepared polymer hydrogel. DAAM was used to form acylhydrazone cross‐linked handles 31 . Simply put, it was the free radical polymerization of DAAm and AAm to form a hydrogel in the presence of ADH and borate bonds and hydrogen bonds.…”