Influence of Molecular Weight of Polysaccharides from Laminaria japonica to LJP-Based Hydrogels: Anti-Inflammatory Activity in the Wound Healing Process

Abstract

In this study, polysaccharides from Laminaria japonica (LJP) were produced by the treatment of ultraviolet/hydrogen peroxide (UV/H₂O₂) degradation into different molecular weights. Then, the degraded LJP were used to prepare LJP/chitosan/PVA hydrogel wound dressings. As the molecular weight of LJP decreased from 315 kDa to 20 kDa, the swelling ratio of the LJP-based hydrogels rose from 14.38 ± 0.60 to 20.47 ± 0.42 folds of the original weight. However, the mechanical properties of LJP-based hydrogels slightly decreased. With the extension of the UV/H₂O₂ degradation time, the molecular weight of LJP gradually decreased, and the anti-inflammatory activities of LJP-based hydrogels gradually increased. LJP that were degraded for 60 min (60-gel) showed the best inhibition effects on proinflammatory cytokines, while the contents of TNF-α, IL-6, and IL-1β decreased by 57.33%, 44.80%, and 67.72%, respectively, compared with the Model group. The above results suggested that low Mw LJP-based hydrogels showed great potential for a wound dressing application.

Keywords: anti-inflammatory; hydrogel; molecular weight; polysaccharides; wound dressing.

Figure 1

GPC profile (A) and changes of molecular weights (B) of degraded LJP.

Figure 2

The swelling properties of LJP-based hydrogels (A). The cell viabilities of LJP (B) and LJP-based hydrogels (C). The stress-strain curves (D), tensile strength (E), elongation at break (F), and Young’s modulus (G) of LJP-based hydrogels. ^a–d Values with different letters are significantly different (p < 0.05).

Figure 3

Contents of IL-6 on HaCaT cells of different concentrations of LPS treatment (A) and different durations of LPS treatment (B). ^a–e Values with different letters are significantly different (p < 0.05).

Figure 4

The levels of TNF-α (A), IL-6 (B), and IL-1β (C) secreted by HaCaT cells after LJP and LJP-gels treatment. The gene expressions of TNF-α (D), IL-6 (E), and IL-1β (F) in HaCaT cells after LJP-gels treatment. ^A–I Values with different letters are significantly different (p < 0.05). ^a–e Values represent the significant difference between LJP and LJP-gel at the same degradation time (p < 0.05).