Conditioned Medium From The Inflammatory Microenvironment Regulated Functional Pulp Regeneration

The extracellular microenvironment is critical for cell function and tissue regeneration. This study explored the effects of an inflammatory-conditioned medium on stem cells from the apical papilla (SCAP) for functional pulp regeneration. Human dental stem cells (DPSCs) and SCAP were isolated from premolars using enzymatic digestion and explant culture. DPSCs were treated with lipopolysaccharide (LPS) for 48 hours, creating a conditioned medium (LPS-CM). The influence of LPSCM on SCAP proliferation, migration, odontogenic and neurogenic differentiation, and pro-angiogenetic effects were assessed. LPS-5 CM enhanced SCAP growth, migration, alkaline phosphatase activity, and mineralized nodule formation compared to LPS-0 CM. The LPS-5 CM group also showed a higher proportion of Nestin-positive neuron-like cells, while LPS-10 CM suppressed proliferation and differentiation. All LPS-CM groups promoted tube formation by human umbilical vein endothelial cells (HUVEC) in vitro. These findings indicate that a moderate inflammatory microenvironment possesses a promoting effect on functional pulp regeneration. Evaluating the effects of LPS-CM on pulp regeneration may provide valuable insights into the role of the inflammatory microenvironment in clinical regenerative endodontic therapy.