Postdoc Research Fellow University of Bergen Bergen, Hordaland, Norway
Abstract: Dental pulp stem cells (DPSCs) are considered prominent in regenerative dentistry for their multipotency, with biobanks established to preserve these cells for therapeutic purposes. However, the extent to which their angiogenic potential and ability to undergo endothelial differentiation are retained after long-term biobanking remains underexplored. Using high-throughput analyses, including RT-qPCR arrays targeting 42 angiogenesis-related genes, reverse-phase protein arrays profiling 141 CD markers, flow cytometry, and digital western blotting, we evaluated DPSCs stored in a biobank for over five years. Pro-angiogenic functionality was validated using a microfluidic organ-on-chip system, a chicken chorioallantoic membrane (CAM) assay, and 3D culture in clinical-grade GelMA hydrogels. Endothelial induction resulted in the upregulation of key endothelial genes, including PECAM1 (CD31) and KDR (VEGFR2) at the mRNA level, though protein-level analyses revealed limited expression of endothelial markers, with cells retaining a predominantly pericyte-like expression profile. The organ-on-chip system confirmed that DPSCs, despite low CD31-positive cell counts, acted primarily as pericytes and myofibroblasts to generate perfusable, water-tight vascularised tissue when co-cultured with Human umbilical vein endothelial cells (HUVECs). However, when implanted into the CAM assay (i.e., chicken tissue), human-derived vasculature expressing CD31 was sporadically observed. Furthermore, 3D culture in GelMA hydrogel under endothelial induction for 45 days enabled the biofabrication of vascularised tissue solely by DPSCs. These findings highlight the strong pro-angiogenic potential of DPSCs, largely mediated through their pericyte-like functions, maintained after long-term biobanking. Additionally, under specific conditions, DPSCs may be capable of vasculogenesis solely through either enhanced endothelial differentiation or the selective expansion of endothelial progenitors within their population.
