C10 - Nitric Oxide-Releasing Nanomatrix and Hydroxyapatite on Angiogenesis and Dentinogenesis

Introduction: : Adequate vascular support and proper dentin repair and mineralization are essential for the maturation of pulp-dentin tissue while mitigating extensive surgical approaches and restorations. To achieve adequate vascular support in the pulp and proper dentin repair and mineralization on the dentin sur-face, we propose nitric oxide (NO) as an angiogen-ic factor and hydroxyapatite (HA) as an inducer of mineralized dentin formation.

Purpose: To study whether NO can promote vascular network formation and whether the com-bination of NO and HA can promote the differentia-tion of dental pulp stem cells (DPSCs).

Materials and

Methods: :

Methods: NO-releasing nanomatrix gel was synthesized using self-assembled peptide am-phiphiles (PA) with Fmoc chemistry to form PA-NO. PA-NO was evaluated on human umbilical vein endothelial cells' (HUVECs) network formation and DPSCs' cellular behavior. Experiments were per-formed with basal media and induced media with and without NO and with and without HA at 7, 14, and 21 days. DPSCs’ proliferation was evaluated using CyQuant®, and differentiation was evaluated using an alkaline phosphatase assay, alizarin red staining, and real-time quantitative reverse tran-scription polymerase chain reaction (qRT-PCR). The migration testing was performed using a mi-crochannel system and a Boyden chamber assay.

Results, Conclusions, and Discussions::

Results: PA-NO induces angiogenic vessel formation on HUVECs in 6 hours compared to a control (p < 0.05). DPSCs’ proliferation increased 2.5-fold with (+)HA in basal media and 2-fold with induction media at 7 days (p < 0.05). DPSCs’ dif-ferentiation by BMP2 gene expression increased 4.8-fold with (+)HA and increased 12.4-fold with (+)NO(+)HA in 7 days (p < 0.01). DPSCs’ migration increased 3-fold with (+)HA and 3.5-fold with (+)NO(+)HA at 24 hours in basal media (p < 0.05).

Conclusions: These results suggest that NO has a positive effect on vascular formation and the combinatory effect of NO and HA on the promotion of DPSCs’ differentiation into dentinogenic cells and consequent mineralization

Acknowledgements and/or References (Optional):: Supported by National Institutes of Health (NIH) Grants R01HL163802 and Alabama Research and Development Enhancement Fund: 1ARDEF22 09 (PI: Ho-Wook Jun) as well as Alabama Research and Development Enhancement Fund: 1ARDEF23 02 (PI: Kyounga Cheon)