IADR Abstract Archives
A Microvascularized Dental Pulp-on-Chip for Studying Vasculogenesis and Pulpitis Modelling
Objectives: Traditional endodontic therapy involves replacing the entire pulp with inert fillings. However, studies have shown that keeping viable pulp increases the success rate of treatment and improves the performance of treated teeth. Vascularization is critical in regenerating dental pulp. Therefore, this study proposed a novel microvascularized dental pulp-on-chip (DPoC) for studying pulp vasculogenesis and modelling pulpitis.
Methods: PDMS-based microfluidic devices were prepared in 3D-printed molds with pulp canal morphology. DPoC constructs were fabricated by mixing dental pulp stem cells (DPSCs) and microvascular endothelial cells (ECs) into human fibrin-based matrix and cultured for 8 days on-chip. Unidirectional flow of media was initiated by a hydrostatic pressure difference between the apical inlet and coronal outlet. Towards modeling a diseased state (pulpitis), DPoC constructs were exposed to heat-killed Fusobacterium nucleatum (Fn) on the coronal end under unidirectional flow conditions. Secretion of cytokines, perfusion, and attachment of THP-1 monocytes to ECs were investigated.
Results: Under flow conditions for 8 days, constructs within the chip displayed excellent vasculogenesis resulting in a perfusable microvascular network. Compared to static conditions, both vessel area and branching index were found to be higher in constructs under flow conditions. DPoC constructs were further characterized by strong expression of vimentin and collagen IV, demonstrating high viability of DPSCs and functional vascular basement membrane. Time-lapse imaging under perfused conditions showed the active movement of THP-1 monocytes through the perfusable microvascular network. Exposure of DPoC constructs to Fn under unidirectional flow directed from the apical towards coronal end significantly reduced the secretion of IL6, IL8, and CCL2, in contrast to flow directed from coronal to apical end. Similarly, attachment of THP-1 monocytes to microvascular network was lower in the apical to coronal flow group.
Conclusions: In conclusion, this study demonstrates the potential to emulate vascularized dental pulp-on-chip and its application to study pulpitis and pulp regeneration.
Methods: PDMS-based microfluidic devices were prepared in 3D-printed molds with pulp canal morphology. DPoC constructs were fabricated by mixing dental pulp stem cells (DPSCs) and microvascular endothelial cells (ECs) into human fibrin-based matrix and cultured for 8 days on-chip. Unidirectional flow of media was initiated by a hydrostatic pressure difference between the apical inlet and coronal outlet. Towards modeling a diseased state (pulpitis), DPoC constructs were exposed to heat-killed Fusobacterium nucleatum (Fn) on the coronal end under unidirectional flow conditions. Secretion of cytokines, perfusion, and attachment of THP-1 monocytes to ECs were investigated.
Results: Under flow conditions for 8 days, constructs within the chip displayed excellent vasculogenesis resulting in a perfusable microvascular network. Compared to static conditions, both vessel area and branching index were found to be higher in constructs under flow conditions. DPoC constructs were further characterized by strong expression of vimentin and collagen IV, demonstrating high viability of DPSCs and functional vascular basement membrane. Time-lapse imaging under perfused conditions showed the active movement of THP-1 monocytes through the perfusable microvascular network. Exposure of DPoC constructs to Fn under unidirectional flow directed from the apical towards coronal end significantly reduced the secretion of IL6, IL8, and CCL2, in contrast to flow directed from coronal to apical end. Similarly, attachment of THP-1 monocytes to microvascular network was lower in the apical to coronal flow group.
Conclusions: In conclusion, this study demonstrates the potential to emulate vascularized dental pulp-on-chip and its application to study pulpitis and pulp regeneration.