ODONTOGENIC/OSTEOGENIC DIFFERENTIATION POTENTIAL OF CONDITIONED MEDIUM DERIVED FROM STEM CELLS FROM EXFOLIATED DECIDUOUS TEETH USING TWO DIFFERENT CENTRIFUGATION-SETTINGS ON PERIODONTAL LIGAMENT STEM CELLS (AN IN VITRO STUDY)

Objectives: evaluation of the odontogenic/osteogenic potential of conditioned medium (CM) harvested from stem cells from human exfoliated deciduous teeth (SHEDs) on the human periodontal ligament stem cells (PDLSCs). Methods: PDLSCs were harvested from sound impacted third molar teeth indicated for extraction while SHEDs were isolated from sound deciduous incisors. SHEDs-CM was collected via two different protocols; (1st protocol entailed centrifugation for 4–5 min. at 440 ×g then the supernatant was collected and re-centrifuged for 1 min. at 4°C at 17,400 ×g, while the 2nd protocol implied centrifugation for 5 min. at 1,500 rpm then the supernatant was collected and re-centrifuged for 3 min. at 3,000 rpm). Assessment of differentiation potential of PDLSCs after culturing with SHEDs-CM prepared by the two protocols was done by monitoring the morphological difference of the odontogenic/osteogenic induced cells upon differentiation, tracing the gene profiles of runt-related transcription factor-2, osteopontin, osteocalcin, alkaline phosphatase and collagen 1, and evaluation of mineral deposition using Alizarin Red staining. Results: PDLSCs assumed round morphology upon differentiation, and statistically significant gene upregulation was recorded in groups that used 1st and 2nd protocols contrasted to the control (P < 0.05), in addition, 2nd protocol groups had significant values when compared to 1st protocols (P < 0.001). Moreover, the production of mineralized nodules was distinguished in groups supplemented with SHEDs-CM as detected by Alizarin Red staining. Conclusions: SHEDs-CM prepared by both protocols possesses the capacity to improve the transformation of PDLSCs into odontogenic/osteogenic lineage, nevertheless, the 2nd protocol possesses a more pronounced differentiation potentials when compared to the 1st one.