Increasing Mechanical Strength of Gelatin Hydrogels by Divalent Metal Ion Removal

Abstract

The usage of gelatin hydrogel is limited due to its instability and poor mechanical properties, especially under physiological conditions. Divalent metal ions present in gelatin such as Ca2+ and Fe2+ play important roles in the gelatin molecule interactions. The objective of this study was to determine the impact of divalent ion removal on the stability and mechanical properties of gelatin gels with and without chemical crosslinking. The gelatin solution was purified by Chelex resin to replace divalent metal ions with sodium ions. The gel was then chemically crosslinked by 1-ethyl-3-(3-dimethylaminopropyl) carbodiimide (EDC). Results showed that the removal of divalent metal ions significantly impacted the formation of the gelatin network. The purified gelatin hydrogels had less interactions between gelatin molecules and form larger-pore network which enabled EDC to penetrate and crosslink the gel more efficiently. The crosslinked purified gels showed small swelling ratio, higher crosslinking density and dramatically increased storage and loss moduli. The removal of divalent ions is a simple yet effective method that can significantly improve the stability and strength of gelatin hydrogels. The in vitro cell culture demonstrated that the purified gelatin maintained its ability to support cell attachment and spreading.

Recent Advances in Photo-Crosslinkable Hydrogels for Biomedical Applications

“…Gelatin is a hydrolysis product of collagen that contains many arginine-glycine-aspartic acid (RGD) sequences and target sequences of matrix metalloproteinase (MMP) that enhance cell attachment and remodeling of thecellular microenvironment, respectively [8,57]. However, gelatin hydrogel exhibits a relatively rapid degradation behavior and poor mechanical strength [58], restricting its biomedical applications. GelMA hydrogel, a gelatin-based hydrogel functionalized with methacrylic anhydride (MA), was first introduced in the year 2000 [59].…”

Synthesis and characterization of thermosensitive gelatin hydrogel microspheres in a microfluidic system

“…Because the bonds that drive this transition are physical hydrogen and van der Waals bonds, the sol-gel transition is thermo-reversible. 26,27 There are several methods for the synthesis of gelatin spheres including spray-drying, 28,29 emulsification, 30,31 and thermal gelation. 32, 33 The advantages of conventional methods are high throughput and mass production.…”

Fabrication and characterization of poly(octanediol citrate)/gallium-containing bioglass microcomposite scaffolds

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