A degradable hydrogel scaffold incorporating the LL-37 for gingival soft tissue regeneration.

Preclinical study involving in vitro cell assays and in vivo animal experiments (rat dorsal skin and gingival defect models) to evaluate a hydrogel scaffold.

“Animal experiments in rats showed that the HA/SF/EGCG/LL37 scaffold significantly increased neovascular density, improved collagen fiber organization and enhanced anti-inflammatory and antioxidant effects versus controls.”

Murine fibroblast cells (L929), human umbilical vein endothelial cells (HUVECs), murine macrophage cells (RAW 264.7), and 8-week-old male Sprague-Dawley rats.

“Healthy 8-week-old male Sprague–Dawley (SD) rats (weight: 220–280 g) were purchased from Liaoning Changsheng Biotechnology Co. Ltd. (Liaoning, China).”

Rats were randomly divided into three groups for both dorsal skin and mucogingival surgery models, with n=5 reported for quantitative histological and wound closure analyses.

“Quantitative analysis of wound area closure (n = 5).”

In vitro release and degradation tests lasted up to 28 days; in vivo dorsal skin wound healing was observed for 14 days, and gingival defect repair was analyzed at 21 days post-implantation.

“The mandibular first molar sites, including alveolar bone and gingiva, were harvested at 21 days for analysis.”

The HA/SF/EGCG/LL37 scaffold exhibited broad-spectrum antibacterial activity against S. aureus, E. coli, and P. gingivalis, and inhibited biofilm formation.

“Overall, the EGCG and LL-37 modified hydrogel scaffold exhibits desirable antibacterial activity, which is advantageous for its application in oral tissue repair within the complex microbial environment.”

The scaffold reduced pro-inflammatory cytokine expression (IL-1β, TNF-α, IL-6) in LPS-stimulated macrophages and scavenged intracellular ROS in oxidative stress models.

“In vitro, it inhibits bacterial growth and adhesion, and significantly reduces pro-inflammatory cytokine expression in LPS-stimulated macrophages.”

In vivo, the scaffold promoted faster wound closure in rat skin defects and increased collagen deposition, VEGF expression, and neovascularization in rat gingival defects compared to controls.

“Animal experiments in rats showed that the HA/SF/EGCG/LL37 scaffold significantly increased neovascular density, improved collagen fiber organization and enhanced anti-inflammatory and antioxidant effects versus controls.”

The study used single-species biofilm models and a rat gingival defect model rather than a true root-exposure model, and long-term clinical translational potential requires validation with multispecies oral biofilms.

“While our current results demonstrate robust antibacterial efficacy against single-species biofilms, the authentic oral environment is characterized by complex microbiomes.”