Gallic acid modified quaternized chitosan/oxidized pectin self-healing hydrogel: antioxidant and antibacterial properties can be adjusted with concentration

Research overview and material design

injectable self-healing hydrogel is regarded as a potential wound dressing material due to its characteristics of adhering to the wound surface and minimally invasive application. In one study, quaternized chitosan (QCS) was physically blended with gallic acid (GA), and then crosslinked with oxidized pectin (OPEC) to prepare hydrogels with different GA contents. The gel behavior, self-healing, swelling degradation, adhesion and mechanical properties, and biological properties of the hydrogels were systematically evaluated. The study was published in the Journal of Biomedical Materials Research Part A.

Key performance data

With the increase of GA content, the gel time was extended from 34 seconds to 477 seconds, but the gel fraction remained above 70%; The self-healing time was significantly reduced from 252 seconds to 19 seconds. The swelling and degradation kinetics showed that the initial loss of unconnected components occurred first, followed by favorable slow surface erosion. The adhesion strength of all hydrogels is between 0.74 and 1.48 kPa, which is in the clinically acceptable range. Rheological analysis showed that the strength of gel decreased with the increase of GA content; The compressive strength also decreased from 109 kPa to 42 kPa.

The biological evaluation showed that the hydrogel had good antioxidant activity, excellent biocompatibility to HDFa cells, and antibacterial activity to Staphylococcus aureus and Escherichia coli (colony reduction> 98%, of which H-0.3GA group had the highest antibacterial effect), and the ability of wound closure in vitro was enhanced after adding GA. It is believed that physical blending provides a simple way to introduce bioactive polyphenols into chitosan based hydrogels, which improves the therapeutic performance through a concentration dependent mechanism, while maintaining the basic characteristics of wound dressings.

Significance to the polymer assistant industry

From the perspective of medical polymer material design, this study suggests that gallic acid, as a bioactive polyphenol, not only contributes to antioxidant and antibacterial functions in chitosan based hydrogels, but also significantly changes the cross-linking and mechanical behavior. It is necessary to balance the gel time, self-healing speed and strength in the formula. For developers who are concerned about the durability and functional stability of medical materials, this type of polyphenol modified system also poses a practical problem: how to maintain the stability of antioxidant function and material structure during sterilization, storage, and use. The technical ideas related to antioxidants and weather stability may provide reference for the functional maintenance and degradation control of similar medical polymer systems, but specific extrapolation still needs to be verified based on actual formulas and processing conditions.

Information source:Optimized Self‐Healing and Antioxidant Hydrogels Based on Gallic Acid–Blended Quaternized Chitosan and Oxidized Pectin for Potential Wound Dressing Applications， Organized by Herun Chemical.