Cell Responses to Conditioned Media Produced by Patient‐Matched Stem Cells Derived From Healthy and Inflamed Periodontal Ligament Tissues

BACKGROUND: Periodontal ligament stem cells (PDLSCs) derived from clinically compromised teeth with periodontitis are considered a readily accessible cell source, but their impaired stem cell functionalities, as observed in various in vitro and in vivo models, necessitate further investigation of these inflamed cells before their translation into therapeutic applications. In this study, the effects of conditioned media (CM) produced by stem cells derived from human healthy periodontal ligament tissues (H-PDLSCs) or inflamed periodontal ligament tissues (I-PDLSCs), referred to as H-CM and I-CM, respectively, on the biologic properties of H-PDLSCs and I-PDLSCs from the same donor are compared to explore the extent to which inflamed cells can be rescued by their extrinsic environment (i.e., by H-CM). METHODS: H-CM and I-CM were prepared from in vitro cell cultures, and the cellular responses of H-PDLSCs and I-PDLSCs to patient-matched H-CM and I-CM were investigated in terms of colony-forming ability, cell proliferation, and adipogenic/osteogenic differentiation. RESULTS: In H-CM and I-CM, H-PDLSCs and I-PDLSCs exhibited similar adipogenic potential. However, when incubated in I-CM, both cell types demonstrated an increased capacity to proliferate but a decreased capacity to differentiate into osteoblasts. Significantly, the impaired osteogenic differentiation of I-PDLSCs was partially rescued by incubation in H-CM under osteo-inducing conditions. CONCLUSION: The CM of patient-matched H-PDLSCs and I-PDLSCs differed, and the impaired osteogenic differentiation of inflamed stem cells had the potential to be rescued, at least partially, for therapeutic use via changing the cell culture microenvironment in vitro.