Int Endod J. 2021 Mar 3. doi: 10.1111/iej.13505. Online ahead of print.
ABSTRACT
AIM: To investigate the effects of a bioactive glass with a high proportion of phosphorus (BG-hP) on the repair and regeneration of dental pulps in rats under an inflammatory microenvironment.
METHODOLOGY: Human dental pulp cells (hDPCs) stimulated with 1 μg/mL lipopolysaccharide (LPS) were cocultured with 0.1 mg/mL BG-hP. Cell proliferation was detected by MTT assays. The expression of inflammation-related genes and odontogenic differentiation-related genes was determined by real-time PCR. Alizarin red staining was used to detect the formation of mineralized nodules. Coronal pulp tissues of rat molars were stimulated with 10 mg/mL LPS and then treated with BG-hP. The expression of inflammation-related genes in pulp tissue was determined by real-time PCR. Haematoxylin-eosin staining and Masson staining were performed to observe the inflammatory response and mineralized matrix formation, after subcutaneous implantation in nude mice, at 3 days and 4 weeks, respectively. Analysis of variance was performed to measure statistical significance (P < 0.05).
RESULTS: BG-hP significantly reduced expression of interleukin-6 (IL-6) and IL-8 and significantly upregulated the expression of IL-10, IL-4 and transforming growth factor-β1 of the LPS-stimulated hDPCs (P < 0.05). BG-hP significantly inhibited the initial cell number (P < 0.05), but the hDPCs stimulated by LPS and cocultured with BG-hP maintained the same proliferation rate as the untreated hDPCs. BG-hP significantly promoted the expression of dentine matrix protein-1 and dentine sialophosphoprotein and the mineralization capacity of the LPS-stimulated hDPCs (P < 0.05). Furthermore, BG-hP significantly downregulated the expression of Il-6 and reduced the inflammatory response of the LPS-stimulated pulp tissue 3 days after subcutaneous implantation (P < 0.05). Four weeks after subcutaneous implantation, BG-hP induced the formation of a continuous layer of dentine-like structure with dentinal tubules and polarizing odontoblast-like cells aligned along it in the LPS-stimulated pulp tissue.
CONCLUSION: The present preliminarily results demonstrated that the bioactive glass with a high proportion of phosphorus inhibited the inflammatory response and promoted the formation of a pulp-dentine complex in a rat experimental model. This study provides a foundation for the construction of materials with the dual functions of exerting anti-inflammatory effects and promoting tissue regeneration to meet the needs of dental pulp repair and regeneration.
PMID:33657647 | DOI:10.1111/iej.13505
