Title: 0866 - The Pulp-dentin Complex-on-a-chip and 3D Bioprinting of Dentin-derived Hydrogels


Luiz Bertassoni (Presenter)
Oregon Health and Science University

Avathamsa Athirasala, Oregon Health and Science University
Anthony Tahayeri, Oregon Health and Science University
Cristiane Fran├ža, Oregon Health and Science University
Jack Ferracane, Oregon Health & Science University
Nelson Monteiro, Oregon Health and Science University
Victor Tran, Oregon Health Science University
Ting Zou, Oregon Health and Science University
Amanda Mushashe, Oregon Health & Science University
Greeshma Thrivikraman, Oregon Health & Science University


Objectives: The pulp-dentin complex represents a unique microenvironment that is challenging to replicate. While the dentin matrix is increasingly seen as a dynamic tissue loaded with diffusible factors, the pulp represents a multi-typic tissue under constant fluid-flow, with well-defined 3D architectures, and spatiotemporal chemical gradients. Here we present two novel platforms that highlight these intricacies of the pulp-dentin complex: 1) a novel model of the pulp-dentin on-a-chip, and 2) 3D bioprinted tissue constructs using hydrogels constituted of dentin-derived molecules and growth factors.

Methods: To develop the pulp-dentin on-a-chip we fabricated a poly dimethylsiloxane micro-fluidic device via a micromolding technique. In the microdevice a microchannel was fabricated directed at a chamber containing a precision-cut dentin fragment, which functions as permeable membrane. Across from the dentin fragment, a stem cell-laden photo-tunable hydrogel was loaded through a microfluidic inlet port, and the whole dentin-hydrogel interface perfused with medium through a separate microchannel. The process of fabrication and the resulting cell-viability in the device were characterized. Regarding the 3D bioprinting, a novel hydrogel bioink composed of dentin collagen and alginate hydrogel blends (2:1, 1:1 and 1:2) were mixed with soluble growth factors extracted from mineralized dentin, and bioprinted with SCAP cells. Cell-viability and differentiation were determined using a live/dead assay kit and RT-PCR. Data was analyzed using ANOVA and Tukey.

Results: The pulp-dentin complex on-a-chip was successfully fabricated and maintained under fluid-flow for at least 5d. Sustained cell-viability was observed across the pulp-dentin interface. The 3D bioprinted constructs showed that the alginate-dentin hydrogels with a 1:2 ratio had higher cell-viability, whereas increasing concentrations of dentin-derived growth factors increased the odontogenic differentiation of SCAP in a dose dependent manner.

Conclusions: The pulp-dentin complex on-a-chip and the 3D bioprinted dentin-derived hydrogels can be useful tools for future pulp regeneration studies and translational applications.


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This abstract is based on research that was funded entirely or partially by an outside source:
NIDCR-NIH (R01DE026170 to LEB), the Medical Research Foundation of Oregon (MRF to LEB) and the OHSU Fellowship for Diversity and Inclusion in Research (OHSU-OFDIR to CF)

Disclosure Statement:
The submitter must disclose the names of the organizations with which any author have a relationship, the nature of the relationship, and the clinical or research area involved. The following is submitted: NONE

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