Effects of Epigallocatechin Gallate, an Antibacterial Cross-linking Agent, on Proliferation and Differentiation of Human Dental Pulp Cells Cultured in Collagen Scaffolds

Introduction: This study aimed to evaluate the efficacy of epigallocatechin gallate (EGCG), an antibacterial cross-linking agent, on the proliferation and differentiation of human dental pulp cells (hDPCs) cultured in hydrogel collagen scaffolds.

Methods: The odontogenic differentiation induced by EGCG was evaluated by alkaline phosphatase (ALP) activity and odontogenic-related gene expression using real-time polymerase chain reaction. The antibacterial effect of EGCG was investigated by a disc diffusion assay in comparison with glutaraldehyde. Proliferation was analyzed by cell number counting under both optical and confocal laser scanning microscopes. To assess the mechanical properties of collagen treated with EGCG, the setting time, surface roughness, and compressive strength were measured.

Results: EGCG itself did not up-regulate the odontogenic-related markers (P > .05) although ALP activity was slightly increased. The proliferation and differentiation of hDPCs cultured in collagen increased significantly in the presence of EGCG (P < .05). The antibacterial activity of EGCG was similar to that of glutaraldehyde. The setting time of collagen was significantly shortened when it was treated with EGCG (P < .05). The surface roughness and compressive strength of the cross-linked collagen were higher than those of collagen without EGCG (P < .05).

Conclusions: Our results showed that EGCG, the antibacterial cross-linking agent, promoted the proliferation and differentiation of hDPCs cultured in collagen scaffolds. Furthermore, the enhanced mechanical properties of collagen scaffolds induced by EGCG may play important roles in cell behavior. Consequently, the application of EGCG to collagen scaffolds might be beneficial for regenerative endodontic therapy.