In situ photo-crosslinked hydrogel promotes oral mucosal wound healing through sustained delivery of ginsenoside Rg1

Abstract

Oral mucosal wounds exhibit an increased susceptibility to inflammation as a consequence of their direct exposure to a diverse range of microorganisms. This causes pain, slow healing, and other complications that interfere with patients' daily activities like eating and speaking. Consequently, patients experience a significant decline in their overall quality of life. Therefore, the pursuit of novel treatment approaches is of great importance. In this study, ginsenoside Rg1, a natural active substance extracted from ginseng root, was chosen as a therapeutic agent. It was encapsulated in a screened photo-crosslinked hydrogel scaffold for the treatment of mucosal defects in the rat palate. The results demonstrated that Rg1-hydrogel possessed excellent physical and chemical properties, and that oral mucosa wounds treated with Rg1-hydrogel exhibited the greatest healing performance, as evidenced by more pronounced wound re-epithelialization, increased collagen deposition, and decreased inflammatory infiltration. Subsequent investigations in molecular biology confirmed that Rg1-hydrogel stimulated the secretion of repair-related factors and inhibited the secretion of inflammatory factors. This study demonstrated that the hydrogel containing ginsenoside Rg1 significantly promotes oral mucosal tissue healing in vivo. Based on the findings, it can be inferred that the Rg1-hydrogel has promising prospects for the therapeutic management of oral mucosal wounds.

Keywords: antiinflammation; ginsenoside Rg1; hydrogel; oral mucosa wound; tissue repair; visible-light crosslinking.

FIGURE 1

(A) Representative formation of the hydrogels in a glass bottle. (B) SEM images. (C) The compressive stress of hydrogels. (D) Swelling study of Hydrogels. The error bar indicates the standard deviation (n = 3).

FIGURE 2

(A) Representative formation of the Rg1-loaded hydrogels in a glass bottle. (B) The molecular structure diagram of ginsenoside Rg1. (C) The molecular structure diagram of GelMA. (D) The molecular structure diagram of LAP. (E) FTIR spectra of pure Rg1, Blank Gel, and Rg1-Gel.

FIGURE 3

(A) The amount of Rg1 released from hydrogels which is measured by High-Performance Liquid Chromatography (HPLC). (B) SEM images. The red arrow indicates the Rg1 particles attached to the pore wall. (C) The cytocompatibility of the Rg1-Gels against human gingival fibroblasts (n = 5).

FIGURE 4

(A) The schematic illustration of creating the rat palatal mucosal defect model (defects with a diameter of 2 mm). (B) Recorded photographs of palatal mucosal wound creation and hydrogel placement in rats. (a). Before wound creation. (b). Wound creation. (c). Mucosal tissue removed from the wound site. (d). After hydrogel placement on the wound.

FIGURE 5

Photographs of wounds of the control group, Blank Gel group, and Rg1-Gel group on days 0, 1, 3, 5, and 7.

FIGURE 6

H&E staining of rat palatal mucosal defect for the Control, Blank Gel, Rg1-Gel groups on day 5.

FIGURE 7

Masson staining of rat palatal mucosal defect for the Control, Blank Gel, Rg1-Gel groups on day 1 and day 3.

FIGURE 8

(A). Edu-stained proliferative cells in the defect region at 24 and 72 h after operation (B). Percentage of Edu-positive cells in the defective region at different time points (C). Cytokine protein expression associated with soft tissue repair (D). expression of soft tissue repair-related genes.

FIGURE 9

(A). MPO-stained neutrophils in the defect region at 24 and 72 h after operation. (B). Percentage of MPO-positive neutrophils in the defective region at different time points. (C). Inflammation-associated cytokines protein expression. (D). Expression of inflammation-associated genes.