Jarvie Journal - College of Dental Medicine - Columbia University

A Tooth Model Evaluation of Human Dental Pulp Cell Response to PEGDA Hydrogel
Ashkan Davary 1 , Sagaw Prateepchinda 2 , Gunnar Hasselgren 1* , Helen Lu 2*
1 College of Dental Medicine, Columbia University, New York, NY;
2 Department of Biomedical Engineering, Columbia University, New York, NY; *Faculty Mentor
Introduction: More than 24 million teeth receive root canal treatment each year. Current endodontic treatment replaces vital pulp
tissue with synthetic material. Teeth whose pulp tissue has been removed are more vulnerable to injury, which threatens the longevity
of the tooth. Therefore, a treatment which is able to maintain the vitality of the pulp or regenerate pulp tissue provides a preferable
alternative to current endodontic treatment. Synthetic biomaterial scaffolds play an essential role in new tissue formation. An
appropriate scaffold for pulp tissue regeneration should support pulp cell viability, proliferation, and matrix synthesis. Polyethylene
glycol diacrylate (PEGDA) hydrogels have been investigated as matrices for engineering various tissues. PEG hydrogels are
synthetic, biocompatible, hydrophilic polymers composed of 3D interstitial cross-links. These polymers have the advantage of being
injectable, photocrosslinkable, and their mechanical properties can be precisely controlled by altering weight percent, molecular
chain length, and crosslinking density. The current study uses a tooth organ model, which simulates the clinical situation of pulp
tissue regeneration, for evaluating PEGDA-based scaffolds as a substrate for supporting human dental pulp cell regeneration.
Objective: To assess the response of human dental pulp cells in a PEGDA hydrogel cultured within human teeth. Cell viability,
proliferation, mineralization potential, and collagen deposition were analyzed. We anticipate that a PEGDA- based gel will support
pulp cell viability, proliferation, mineralization potential and collagen deposition.
Methods:
Scaffold Preparation & Cell Culture - Human adult dental pulp cells (P.4, explant culture) from molar teeth were seeded in PEGDA
(10kDa, 4.02% w/v) solution at 4.8 million cells/mL, injected into the pulp chamber of sectioned adult molar teeth, photopolymerized
with 0.1% (w/v) Irgacure2959 under UV light (365nm), and maintained in fully supplemented medium with ascorbic
acid. Monolayer cell culture served as control group.
Endpoint Analyses - Samples were analyzed at 7 and 28 days for cell viability (n = 2), cell proliferation (n=6), collagen content
(n=6), alkaline phosphatase (ALP) activity (n=6) and collagen deposition (n=6).
Statistical Analysis - Two-way ANOVA and the Turkey-Kramer post-hoc test were used for all pair-wise comparisons (p