Strong and tough, pH sensible, interpenetrating network hydrogels based on gelatin and poly(methacrylic acid)

Abstract

Hydrogels are promising materials for biomedical applications due to highly hydrated, porous, permeable structure with possibility to accommodate living cells, drugs, or bioactive factors. In this paper, we reported poly(methacrylic acid) (PMAA)/gelatin IPN hydrogels, synthesized by free-radical polymerization, with adjustable mechanical, structural, physicochemical, and biological characteristics. The influence of methacrylic acid (MAA), gelatin, and crosslinker in the precursor solution on hydrogels properties was investigated. The increasing concentration of MAA, gelatin, and cross-linker led to better mechanical properties, lower porosity, and water content. The compressive mechanical properties of hydrogels were significantly better in comparison to a single-network PMAA hydrogel, while the obtained compressive strength values up to 16 MPa were comparable with tough hydrogels. The increasing concentration of MAA and cross-linker reduced fatigue resistance and degradability, while the increase in gelatin content acted in the opposite way. Swelling tests in different pH conditions demonstrated strong pH-sensibility of the hydrogels, which was more pronounced as MAA concentration was higher, and gelatin and cross-linker concentrations were lower. In addition, the hydrogels strongly promoted the proliferation of human periodontal ligament stem cells and MRC-5 cells as assayed by MTT assay.

Novel Trends in Hydrogel Development for Biomedical Applications: A Review

“…IPN hydrogels may be preferred over polymer blends due to their improved mechanical strength, controlled swelling behavior and efficient drug loading capacity [ 259 , 261 ]. One of the most used biopolymers for IPN formation is CTS, as reported by Dragan et al (2020) [ 262 ], although there have been a large number of research papers based on IPN hydrogels synthesized with different synthetic and natural polymers, such as COL [ 263 , 264 , 265 ], GEL [ 266 , 267 , 268 ], alginate [ 267 , 269 , 270 ], polyurethane [ 264 , 265 , 270 ], PVA [ 268 , 271 ], PEG [ 272 , 273 ] and poly (aspartic acid) [ 274 ], among other candidate polymers. In this sense, there is a wide range of possibilities by means of materials and synthesis procedures that can be used for IPNs formation, owing to their outstanding physicochemical properties.…”

Unimpaired highly extensible tough chemically crosslinked hydrogel after experiencing freeze/thaw and boiling processes

“…Depending on the design, the material properties can be manipulated to fit specialized requirements, such as being highly stretchable and tough. [1][2][3][4] The unique properties of hydrogels have found them an important role in a wide range of fields like soft robotics, agriculture, and biomedical applications, including tissue engineering, contact lenses, drug delivery, and wound dressing. [5] For many applications, it is important that the hydrogel has proper mechanical properties specific to the application.…”

Bioinspired Hydrogels as Platforms for Life-Science Applications: Challenges and Opportunities

“…Chitosan and poly(vinyl alcohol) form full-IPNs with mechanical strength and resistance to wear [67]. Poly(methacrylic acid)/gelatin hydrogels, with tunable structural, physicochemical, mechanical, and biological properties were obtained by free-radical polymerization of methacrylic acid in presence of gelatin [68]. These hydrogels were pH-sensitive with compressive strength up to 16 MPa and allowed the cell proliferation.…”