Characterization of Fibronectin-Adherent, Non-Fibronectin-Adherent, and Explant-Derived Human Dental Pulp Stem Cell Populations

<b>Background/Objectives:</b> Dental pulp stem cells (DPSCs) are of significant interest due to their mesenchymal lineage and relative availability from extracted teeth. This study aims to examine the relationship between fibronectin-adherent, non-fibronectin-adherent, and explant-derived DPSC populations in terms of the population doubling rate in culture and the expression of mesenchymal cell surface markers and their capacity for osteodifferentiation. <b>Methods:</b> Human pulp tissue was removed from healthy extracted human teeth, enzymatically digested prior to seeding onto fibronectin-coated plates, and left to adhere for 20 min, yielding a fibronectin-adherent population. The remaining non-adherent cells were transferred and designated 'non-fibronectin-adherent.' Intact pulp was placed on uncoated plastic for 5 days, with the migrated cells designated 'explant-derived'. DPSCs from these populations were examined in terms of population doubling rates, the expression of CD90, CD44, CD105, and CD73, and the expression of <i>RUNX2</i>, <i>SPP1</i>, and <i>BGLAP</i> after 7 days in osteoinductive media. <b>Results:</b> The fibronectin-adherent cells had the greatest population doubling over time. All populations demonstrated comparable percentages of cells positive for mesenchymal markers, though individual marker expression varied slightly. The explant-derived cells showed increased expression of <i>RUNX2</i> after 7 days in osteoinductive media, while the treated single-cell-suspension-derived populations showed increased expression of <i>SPP1</i> mRNA. <b>Conclusions:</b> Fibronectin enrichment resulted in a population with the greatest rate of population doubling over extended culture compared to the other two populations. The proportion of cells positive for all four mesenchymal surface markers was the same between populations. The fibronectin-adherent and non-adherent cultures may have responded more rapidly to osteoinductive media than the explant-derived cells.