Reactive Oxygen Species Suppressive Kraft Lignin‐Gelatin Antioxidant Hydrogels for Chronic Wound Repair

Abstract

Chronic wound is difficult to repair because the normal wound healing mechanism is inhibited by the continuous inflammatory response. The delayed inflammatory responses generate high level of reactive oxygen species (ROS) at the wound sites, which leads to a longer inflammatory phase and induces a vicious cycle that interferes with the normal wound healing process. Therefore, ROS scavenging is an important factor for chronic wound healing. In this study, antioxidant hydrogel is developed by cross-linking kraft lignin, an antioxidant agent, and gelatin (Klig-Gel). Klig-Gel hydrogel is fabricated via ring opening reaction with epichlorohydrin as a cross-linker. High ROS scavenging activities are confirmed by various antioxidant evaluations, and in vitro natural antioxidant expression tests show reduction of oxidative stress. Mechanical properties of Klig-Gel hydrogel are tailorable by introducing different amount of kraft lignin to the hydrogel system. Biocompatibility is confirmed regardless of the kraft lignin content. Klig-Gel hydrogel is a promising ROS scavenging material that can be applied in various chronic wound healing applications.

Bio‐Inspired Antioxidant Heparin‐Mimetic Peptide Hydrogel for Radiation‐Induced Skin Injury Repair

“…[28] At the same time, excessive infiltration of macrophages and large amounts of inflammatory cytokines produced by neutrophils can cause more immune cells to accumulate, leading to a vicious cycle of continuous inflammatory phases in the wound-healing process. [29] Therefore, suppression of inflammation and reduction of inflammatory cell infiltration are essential for the healing of radiation-reduced skin injury. The anionic sulfate group on the 4-sulfobenzoic acid at the end of the K16 peptide can be complex with positively charged inflammatory cytokines, thus achieving the effect of eliminating inflammation.…”

Lignin, the Lignification Process, and Advanced, Lignin-Based Materials

“…The many functional groups of lignin can be employed to integrate lignin fragments in sustainable and environmentally friendly hydrogels, which are recognized for their interesting applicability in biomedicine [258]. As example, an antioxidant hydrogel was created by crosslinking KL (acting as antioxidant agent) and gelatin in water [259]. The hydroxy group from KL and the primary amine groups from gelatin were reacted with epichlorohydrin under alkaline condition, whereby covalent bonds were formed in a ring-opening reaction.…”