A Novel Strategy to Engineer Pre-Vascularized Full-Length Dental Pulp-like Tissue Constructs

Avathamsa Athirasala,Luiz E Bertassoni,Fernanda Lins,Anthony J Smith,Jack Ferracane,Anthony Tahayeri,Christine Sedgley,Monica Hinds

doi:10.1038/s41598-017-02532-3

Abstract

The requirement for immediate vascularization of engineered dental pulp poses a major hurdle towards successful implementation of pulp regeneration as an effective therapeutic strategy for root canal therapy, especially in adult teeth. Here, we demonstrate a novel strategy to engineer pre-vascularized, cell-laden hydrogel pulp-like tissue constructs in full-length root canals for dental pulp regeneration. We utilized gelatin methacryloyl (GelMA) hydrogels with tunable physical and mechanical properties to determine the microenvironmental conditions (microstructure, degradation, swelling and elastic modulus) that enhanced viability, spreading and proliferation of encapsulated odontoblast-like cells (OD21), and the formation of endothelial monolayers by endothelial colony forming cells (ECFCs). GelMA hydrogels with higher polymer concentration (15% w/v) and stiffness enhanced OD21 cell viability, spreading and proliferation, as well as endothelial cell spreading and monolayer formation. We then fabricated pre-vascularized, full-length, dental pulp-like tissue constructs by dispensing OD21 cell-laden GelMA hydrogel prepolymer in root canals of extracted teeth and fabricating 500 µm channels throughout the root canals. ECFCs seeded into the microchannels successfully formed monolayers and underwent angiogenic sprouting within 7 days in culture. In summary, the proposed approach is a simple and effective strategy for engineering of pre-vascularized dental pulp constructs offering potentially beneficial translational outcomes.

Highlights

Root canal treatment is necessary in the event of deep caries or trauma when the homeostasis of the pulp tissue is lost
TM hydrogel (Puramatrix ) encapsulated with dental pulp stem cells (DPSCs) and human umbilical vein endothelial cells (HUVECs) to determine the role of DPSCs in the angiogenic process, and partially regenerate dental pulp in root canals implanted in the back of immunocompromised mice[14, 16]
gelatin methacryloyl (GelMA) hydrogels have been extensively utilized for a variety of tissue engineering applications, to the best of our knowledge, these scaffold materials remain little explored regarding their application for dental pulp regeneration[26]

Summary

Introduction

Root canal treatment is necessary in the event of deep caries or trauma when the homeostasis of the pulp tissue is lost. TM hydrogel (Puramatrix ) encapsulated with dental pulp stem cells (DPSCs) and human umbilical vein endothelial cells (HUVECs) to determine the role of DPSCs in the angiogenic process, and partially regenerate dental pulp in root canals implanted in the back of immunocompromised mice[14, 16] These strategies require time intensive biological processes for a functional and interconnected vasculature to be formed. To prevent hypoxic conditions in the tissue until neo-vasculogenesis occurs, we contend that an engineered vasculature that is present from the onset of the regenerative process represents an improved strategy for regeneration[24] of vascularized dental pulp To address these challenges, we present a novel strategy to fabricate pre-vascularized pulp-like hydrogel tissue constructs in full-length root canals in-vitro (Fig. 1A–D). We report proof of principle experiments utilizing animal cell sources that are not compatible with direct clinical applications, and are only intended at initial screening of the developed protocols, we argue that the proposed approach may form the basis for a simple and effective strategy for the engineering of vascularized dental pulp with potentially beneficial translational outcomes

Methods

Results

Conclusion