title: Modulation of Dental Pulp Stem Cell Odontogenesis in a Tunable PEG-Fibrinogen Hydrogel System.
abstract: Injectable hydrogels have the great potential for clinical translation of dental pulp regeneration. A recently developed PEG-fibrinogen (PF) hydrogel, which comprises a bioactive fibrinogen backbone conjugated to polyethylene glycol (PEG) side chains, can be cross-linked after injection by photopolymerization. The objective of this study was to investigate the use of this hydrogel, which allows tuning of its mechanical properties, as a scaffold for dental pulp tissue engineering. The cross-linking degree of PF hydrogels could be controlled by varying the amounts of PEG-diacrylate (PEG-DA) cross-linker. PF hydrogels are generally cytocompatible with the encapsulated dental pulp stem cells (DPSCs), yielding >85% cell viability in all hydrogels. It was found that the cell morphology of encapsulated DPSCs, odontogenic gene expression, and mineralization were strongly modulated by the hydrogel cross-linking degree and matrix stiffness. Notably, DPSCs cultured within the highest cross-linked hydrogel remained mostly rounded in aggregates and demonstrated the greatest enhancement in odontogenic gene expression. Consistently, the highest degree of mineralization was observed in the highest cross-linked hydrogel. Collectively, our results indicate that PF hydrogels can be used as a scaffold for DPSCs and offers the possibility of influencing DPSCs in ways that may be beneficial for applications in regenerative endodontics.
authors.affiliation: Faculty of Dentistry, National University of Singapore, 11 Lower Kent Ridge Road, Singapore 119083.
authors.forename: Qiqi
authors.initials: Q
authors.lastname: Lu
authors.affiliation: Faculty of Dentistry, National University of Singapore, 11 Lower Kent Ridge Road, Singapore 119083.
authors.forename: Mirali
authors.initials: M
authors.lastname: Pandya
authors.affiliation: Department of Surgery, Yong Loo Lin School of Medicine, National University Health System, National University of Singapore, 1E Kent Ridge Road, Singapore 119288.
authors.forename: Abdul Jalil
authors.initials: AJ
authors.lastname: Rufaihah
authors.affiliation: Faculty of Dentistry, National University of Singapore, 11 Lower Kent Ridge Road, Singapore 119083.
authors.forename: Vinicius
authors.initials: V
authors.lastname: Rosa
authors.affiliation: Faculty of Dentistry, National University of Singapore, 11 Lower Kent Ridge Road, Singapore 119083.
authors.forename: Huei Jinn
authors.initials: HJ
authors.lastname: Tong
authors.affiliation: Nanoscience and Nanotechnology Initiative, Faculty of Engineering, National University of Singapore, 2 Engineering Drive 3, Singapore 117581 ; Faculty of Biomedical Engineering, Technion-Israel Institute of Technology, 32000 Haifa, Israel.
authors.forename: Dror
authors.initials: D
authors.lastname: Seliktar
authors.affiliation: Faculty of Dentistry, National University of Singapore, 11 Lower Kent Ridge Road, Singapore 119083 ; Tissue Engineering Program, Life Sciences Institute, National University of Singapore, 27 Medical Drive, Singapore 117510.
authors.forename: Wei Seong
authors.initials: WS
authors.lastname: Toh